Forrest M. Council
University of North Carolina
Highway Safety Research Center
730 Airport Road
Chapel Hill, NC 27599-3430
Yusuf M. Mohamedshah
LENDIS Corporation
Turner Fairbank Highway Research Center
Federal Highway Administration
6300 Georgetown Pike
McLean, VA 22101-2296
Federal Highway Administration
Office of Safety and Traffic Operations Research &
Development
U.S. Department of Transportation
Washington, DC 20590
Revised, August 2007
(NOTE: Changes from the previous edition of the Guidebook are shown in bold and italic.)
The Minnesota data system includes the following basic files:
For ease of use, the three accident subfiles, the Roadlog File, and the Intersection File have been converted to SAS files. The Traffic file (volume data) and data from the Reference Post file (True Mileage) have been merged with the Roadlog file beginning with 1990 data, and no longer exist as separate files within HSIS. The Roadlog file prior to 1990 has only the traffic data merged. Raw file data are provided to the Highway Safety Research Center (HSRC) where they are retained as backup information. The documentation (variable listings, definitions, etc.) for these raw files and for the SAS files that are developed from them are available at Federal Highway Administration (FHWA) offices.
Beginning in 2004, the HSIS system was converted from SYBASE relational database to ORACLE relational database for internal use. This ORACLE database stores the data received from Minnesota and other States, and the data files for a given State are linked and manipulated using SAS code. However, this conversion from the original SAS-based system to the ORACLE relational system is somewhat transparent to the end-user of the data since the output files produced by ORACLE for modeling and analysis will be SAS formatted. As in the past, we have continued to produce SAS format libraries for each of the variables in each of the files. Because it is envisioned that the majority of analyses will utilize these SAS files and formats, this Guidebook will concern these SAS files - their formats, completeness, and quality.
The accident data are in three separate subfiles, the first containing the basic accident information on a case-by-case basis, and then separate files containing information on vehicles and occupants (injured occupants in 1985-90, injured plus some uninjured occupants in 1991, and all occupants beginning in 1992) in each accident case. The vehicle and occupant data (which includes pedestrians and bicyclists) can be linked to the basic accident data for a specific case using the accident report number and vehicle number. Again, please note the change in the file to all occupants for 1992 and later. The accident subfile can be linked to the other major files (e.g., Roadlog, Intersection/Interchange) using three common variables -- route-system, route-number, and reference point. Beginning in 1991 the Minnesota Department of Transportation (MnDOT) made extensive changes in their accident reporting system. These will be described in more detail in the later text.
Unlike an Accident File record which is referenced to a point on the roadway, each record on the Roadlog File contains information on a homogeneous section of roadway (i.e., a stretch of road which is consistent in terms of characteristics), with each new section being defined by a new beginning reference point. Each record on this Roadlog File contains current characteristics of the road system including surface type and width, shoulder and median information, lane information, etc.
The Reference Post ("True Mileage") File received from MN contains "true mileage" information on some of the sections within the Roadlog File, primarily the Interstate and major arterials. This information is used in the calculation of the lengths of homogeneous sections in the Roadlog File where available. For sections where Reference Post File data do not exist, the section length is estimated by subtracting the beginning milepoints for two consecutive sections of roadway. In 1990, HSIS staff conducted comparative analyses to determine whether the lack of "true mileage" information on some lower-order roadway sections significantly affects the section-length data and subsequent crash rate calculations. In summary, the analyses indicated that the use of length estimates based on milepoints (where "true mileage" is absent) does not appear to result in a significant error, i.e., the use of the length estimates based on mileposts appears sufficiently accurate for analyses conducted with HSIS data. (A fuller description of these analyses and findings is available from HSIS staff.) Again, please note that beginning with 1990, pertinent data from the Reference Post File were merged with the Roadlog file and the entire file is no longer available as a separate file on the HSIS system.
The Traffic File contains estimated count information (yearly AADT's) for a series of count stations located on all roadways described in the Roadlog File. It is maintained by the eight different MnDOT District Offices. This AADT information can be linked with the sections on the Roadlog File using the reference point. This file also contains AADT's for heavy commercial vehicles which are defined as vehicles with two axles and six tires or larger. The file is updated on a two-year cycle, and indications are that these traffic count data are excellent for the trunkline system and fairly good for the county state-aid systems. Again, please note that traffic data were merged with the Roadlog File beginning in 1987. The Traffic File also still remains a separate file on the HSIS system for years 1987 thru 1989, but is no longer available as a separate file on the HSIS system after 1989.
The Intersection/Interchange File contains information concerning intersections on major roadways that are maintained by the eight different MnDOT Districts across the state. It contains a number of different variables including approach lane information, entering AADT, intersection control type, and added details for signalized intersections. The file will contain intersections of US/US, US/state, and all interchanges.
Due to established priorities of effort, HSRC staff did not work with the Bridge File or the Railroad Grade-Crossing File. As is the case with most States, the Bridge File data contain information on bridge structures across the State. The data are considered quite accurate since it is based on the federal bridge inventory. It is also noted that the MnDOT Bridge Division that updates this file has a file of pictures of each bridge that is greater than 10 feet in length. In a similar fashion, the Railroad Grade Crossing File is a file containing information on all grade-crossings in the State, and is prepared and maintained according to FHWA requirements.
Details of the Accident, Roadlog, and Intersection/Interchange files and the traffic data are presented in the following section.
Minnesota law requires that an accident report be filed by the investigating police officer whenever there is injury in the crash or property damage of greater than $500. The property damage threshold increased to $1,000 in August, 1994. The accident data are controlled by the Department of Public Safety (DPS), where a group of coder/editors not only keys in the data, but also locates each of the accidents based on the inputs provided on the report by the investigating officer and a series of maps showing the route identification and locations of prominent features and intersections. While incorrectly coded locations are identified by MnDOT edit programs and are passed back to the coders for possible correction, DPS staff limitations have prevented correction of all such errors. Thus, from an engineering analysis standpoint, there remain some location errors in the system. However, given the relatively small percentage of location errors identified and the fact that the main result of these errors is to reduce the sample size of available accidents (a problem partially overcome by the large samples available for most HSIS-type analyses), the location information should be of higher quality than in most States. It is also noted that accidents that occur on interchange ramps are located to the center of the interchange. Thus, in bridge-related analyses, if the major route crosses over the minor route, the ramp accidents will be (erroneously?) located to the bridge.
MnDOT send an annual accident file to HSIS each year. Currently, there are 21 years of accident data in the linkable Minnesota files obtained for the HSIS -- 1985-2005. Prior to 1991, the original data set received from Minnesota included approximately 90,000 accidents per year and approximately 170,000 vehicles per year. However, for use in the HSIS system, the "citizen reports" (i.e., code "0" under "Officer Type") have been deleted due to both missing data and inherent biases in these reports. In addition, the very limited number of crashes which cannot be linked to the roadway file have also been deleted. This process has left approximately 71,000 - 86,000 crashes and 132,000 - 160,000 vehicles in the HSIS files for 1985-2005.
The number of crashes increased from 71,000 up to 86,000 with some fluctuations. Based on conversations with MnDOT staff, the fluctuations may have been due to increased snow/ice and related increases in crashes. Changes in the numbers of vehicles in the HSIS Vehicle subfiles track the changes in accidents very closely- there are no "abnormal" years. Indeed, the ratio of vehicles/crash is between 1.83 and 1.87 for this full 21-year span.
Beginning in 1991, the Minnesota Department of Public Safety made extensive changes in their accident reporting system. These changes affect both the coverage and accuracy of the data in the HSIS files. The changes that have had the most effect on the HSIS system are as follows: (1) changed computer platforms from IBM MVS to VAX (March 11, 1991) which changed data coding screens and codes; (2) changed the accident report form in January 1991; (3) initiated a state-wide campaign to promote the use of the new report forms. The effects of these changes are noticeable in both the 1990 and later occupant data. (Note that there may also be changes in the overall accident severity distributions beginning in 1995 and later, given that the property-damage-only reporting threshold changed to $1000 in August, 1994.)
The Vehicle and Occupant subfiles are similar in format to those in other states. The Vehicle Subfile contains variables on both the vehicle (e.g., make, model, type, direction traveling, contributing factors), and on the driver (e.g., age, sex, physical condition). The Vehicle Subfile also contains information on a four-part sequence of events for each vehicle, which provides more detail on vehicle "paths" than do most state files. The Occupant subfile contains information on such descriptors as age, injury, position in vehicle, ejection, etc. for each occupant in the vehicle, including the driver. It is again noted that the occupant records are not total occupant records for years 1985-1989, but simply consist of those occupants who are injured in the crashes. For those earlier years, there are approximately 39,000 occupants in the file each year. While coding of uninjured occupants began in 1990, it appears that complete coding on all occupants is present in 1992 and later years. Except of this major change, the only other change in the Occupant Subfile across the time frame was in 1996 and later, when the number of occupants per vehicle increased by approximately 10% over the preceding years. Conversations with MnDOT staff indicate that they began adding additional "placeholder" occupant records in this file so that the total number of records in the Occupant File for a given vehicle matched the "number of occupants" for that vehicle as entered by the investigating officer. The assumption was that the officer would record the "count" variable correctly, but might not include data on each uninjured occupant. Based on the pattern in the file, our assumption is that these "placeholders" were added beginning in 1996.
Information related to data completeness and accuracy in these three subfiles is based on three sources -- conversations with Minnesota staff who use the data, information developed through past use of the data by HSIS staff and other researchers, and comparisons of a series of single-variable tables for key variables in each file with the same variables in all other years. This latter set of quality control checks is conducted each year that a new file is received from MnDOT.
A check of the percent "unknown" for each variable in the files indicated that, once citizen and "unknown-officer" reports are removed, almost all the variables studied show a very low percentage of unknowns or obviously miscoded variables -- usually around l-3 percent of the total sample in each variable. The 1991 file seems to have a slightly higher percent of unknown codes than the earlier or later years, but the 1992 and later years' percent seldom exceeds 4 percent.
In terms of data accuracy, a series of comparisons were made of variables which should have been somewhat similar on the accident file according to their definitions. In general, the variables were found to be internally consistent. For example, a comparison of the number of vehicle records with a count of single and multi-vehicle crashes matched quite accurately. The urban/rural codes matched well with "investigating officer" codes, and the location of pedestrian/bike accidents matched well with accident type. The variable indicating "interchange-related" compared well with the number of interchange elements noted in a separate variable, and counts of traffic control devices in accidents were found to match well with the number of intersection-related crashes.
However, there are two variables whose coding formats may lead to inconsistent or erroneous data. First, (like most other States) the driver-related "physical condition" variable on the vehicle subfile has categories which are clearly not mutually exclusive. For example, while only one code is allowed, a driver could be both "under the influence" and "ill" or "handicapped". Conversations with Minnesota accident officials indicate that the officers are most likely to code alcohol involvement if a choice is present. Second, the variable related to "safety equipment" in the injured-occupant subfile includes a mixture of codes related to occupant restraints, motorcycle helmet and headlight use, and pedestrian clothing colors. As verified by Minnesota, the layout of this variable makes it very difficult to code correctly, and they are planning to modify this variable in the future. For now, the data are suspect.
In addition, inconsistencies were noted in comparisons of three variables related to the type of accident – "accident diagram", "accident type", and "vehicle movement" in the accident. Conversations with Minnesota accident records officials indicated that the "accident diagram" variable is often recoded (corrected) by coders who review each of the accident reports, while the coding for "accident type" is captured as recorded by the officer. The coding for "vehicle movement" is (subjectively) assigned by the coders to reflect the nature of movement based on the officer's description. (Note that "vehicle movement" was not coded for 1990 and later data.) Since the "accident diagram" variable describes the general nature of the vehicle movements in the crash, it would be expected to be consistent with the vehicle movement prior to accident. However, there were major inconsistencies noted in the comparison of the two variables. There are many more possible categories within the second variable related to vehicle movement, and there were notable inconsistencies between the percentages within accident types that would be expected to match certain vehicle maneuvers. In this case, because it is corrected by the in-house coders, it may be somewhat more accurate to use the accident diagram variable for this application.
In a similar comparison of "accident diagram" with "accident type" (when driver self-reports are deleted), consistency was found for many of the categories which should be related. For example, 90 percent of the accident diagram "ran-off-road left" codes were noted under accident type to be either collisions with fixed objects or rollovers. However, further examination revealed that the accident diagram variable provides the general nature of the crash without reference to what is involved. For example, for those crashes coded as "head-on" in the accident diagram variable (which one might assume means head-on with a second moving vehicle), 40 percent were coded as "collision with motor vehicle in transport", and 5 percent were coded as "collision with parked motor vehicle" in the accident type variable. In like fashion, 15 percent of "sideswipe - opposite direction" under the accident diagram variable were "collisions with parked vehicle" in the accident-type variable. Clearly, if the analyst is interested in "what" is struck (e.g. another vehicle) in what fashion (e.g. head-on), then some combination of both variables should be used.
Further HSIS analyses using the "accident diagram" variable have also indicated that the "head-on" and "sideswipe opposing" codes reflect the direction of the opposing vehicles immediately prior to impact rather than their initial direction. While this coding procedure is correct, it does affect analyses in which the researcher is attempting to isolate, say, head-on or sideswipe crashes involving opposing vehicles. For example, many of the "head-on" or "sideswipe" crashes on multilane facilities, which one might assume to be cross-median crashes, actually involve vehicles originally traveling in the same direction where one of the vehicle spun around (perhaps due to ice or wet pavement) and struck the other vehicle front-to-front or side-to-side. Again, this does not represent a coding error (since no other alternative is easily proposed), but will affect certain analyses where the type of crash is used to imply something about original direction of travel.
Additional HSIS analysis indicates less than total agreement between two variables which should define whether or not an accident is intersection-related – "intersection relationship" and certain groups of codes within "vehicle movement". Note that the former is coded by the officer on the scene, and the latter is coded in-house by coders based on the sketch and narrative. Since there is no clear choice between the two, one possibility is to use a combination of the two (requiring both to be coded as "intersection-related"), a procedure which would result in a conservative definition of a crash's relationship to an intersection.
Use of the LOC_TYPE variable concerning "Intersection Relationship" has also indicated some problems with the data related to interchange ramps on divided roadways. A full discussion of the problem is found in the "NOTE" under the variable in the SAS formats.
Finally, the changes in the 1991 accident report system affected the consistency and accuracy of the data in comparison to earlier years. Certain categories in specific variables changed in either frequencies (e.g., "collision with vehicle other roadway" in ACCTYPE increased), and coding (e.g., "not applicable" changed to "no object struck" under the "fixed object struck" variable for 1991, but not for 1992 and later). When questioned about these differences in the data, Minnesota staff indicated that (1) some data entry edits were not in place in the early use of the new system, allowing inclusion of some invalid data values for some variables; (2) the new system has automatic default values for data entry screens, and in initial use of these screens, the data entry personnel may not have replaced the default values with actual codes from the accident report form; (3) wording of the accident report form changed for some variables, which could have led to different interpretations of the appropriate code to check on the new form; and (5) the new accident report form increased the number of "other" and "unknown" categories available for use by the officer. It should also be noted that the code changes for data in 1990 and 1991 made some variables inconsistent with the prior years of data (1985-89). To correct this problem, where possible, 1990 and 1991 data with code changes for existing variables were re-coded to match earlier years.
In summary, analysis of the Minnesota accident files indicated that the files are, in general, quite accurate and internally quite consistent with few exceptions. The 1991 changes did result in some new codes and some inconsistency with prior years' data, particularly for the 1991 data. The 1992 and later data appear to again be consistent with fewer uncoded cases than in 1991. Where high percentages of uncoded data or possible inaccuracies/inconsistencies have been found, a "NOTE" has been included under the variable listing in the later format section of this Guidebook.
As noted above, the Roadlog file contains current characteristics of the road system. The 135,000-mile system contains approximately 12,000 miles of the primary "trunk" roadway, 33,000 miles of additional state-maintained county and municipal systems, and 90,000 miles of (non-state maintained) county and local roads. Table 1 provides a breakdown of the 55,000 miles of paved, two-way roadway and 80,000 miles of "other" roadway in the state (i.e., either unpaved or county/local roads without complete inventory information).
The state maintained portion of the file is basically updated daily based on construction and maintenance plans and input from the local division engineers. Data changes are extracted from these plans and are activated in the system on the date that the project has been completed. An "effective date" is placed on the file at that time to indicate that one or more of the variables for that roadway section have been changed.
| Roadway Category | Mileage |
|---|---|
| Urban freeways | 350.95 |
| Urban freeways < 4 Lanes | 2.24 |
| Urban multilane divided non-freeways | 847.67 |
| Urban multilane undivided non-freeways | 532.73 |
| Urban 2 In highways | 12,085.07 |
| Rural freeways | 712.65 |
| Rural freeways < 4 Ins | 0.35 |
| Rural multilane divided non-freeways | 938.64 |
| Rural multilane undivided non-freeways | 73.34 |
| Rural 2 In highways | 38,878.82 |
| Other | 80,957.75 |
| Total | 135,380.20 |
Again, the DPS makes a frozen copy of the roadlog file annually for submission to HSIS. However, unlike other states, this is not done at the end of the calendar year, but at the time when the accident file is finalized for a preceding year. This is usually between March and July of the following year. The file received by HSIS from MnDOT contains approximately 303,000 records. Approximately 103,000 of these records are "false" records used to signify ends of routes, beginnings of coinciding routes, gaps in sections, and other records needed to allow analysis of the files. These "false" records are flagged by values in the "Remark" variable, and, thus, any record with blanks in this variable (approximately 220,000 "true" records) represents a section of "homogeneous" roadway where characteristics remain constant. For the 1994 and later HSIS files, all "false" records are deleted.
These 220,000 records cover approximately 135,000 miles of roadway. The HSIS system currently contains fifteen Roadlog files, representing current characteristics in 1989-1992, 1994-1996 and 1998-2005. (The 1987 file, which was originally in the HSIS system, could not be reformatted for consistency in recent file modifications. Thus, it is no longer a part of the system. The 1993 file was omitted from the system due to missing mileage in the raw file. The 1997 file received could not be linked with crash data. The analyst can link the 1997 crash data with either the 1996 or 1998 files.) Because of the complexity of the necessary programming, computer checks for changes in each variable between years were not conducted, but conversations with Minnesota staff indicate that only a very small proportion of the file would be expected to change each year.
The number of total crashes in 2003 is approximately 10,000 lower than for prior or subsequent years. Conversations with MN DOT staff indicated that this was during a transition to a new crash reporting system, and that almost all of the decrease would be in non-injury (PDO) crashes. HSIS quality control runs on critical variables indicated that the 2003 distributions are similar to other years. However, the user should be aware of this bias in the data.
Two new variables, RODWYCLS and MVMT, have been created by HSIS staff in the roadway segment file of each of the HSIS states. The RODWYCLS (Roadway Class) variable is based on the combination of rural/urban, access control, number of lanes and median type variables. This variable classifies each roadway segment into one of ten roadway types described in the later "Format" section. This variable is also included as an accident-file variable by matching each crash to its corresponding roadway segment. The MVMT variable (Million Vehicle Miles of Travel) is calculated for each segment in the roadway file by multiplying the segment length, AADT and 365 days in a year, and dividing by one million. Both these variables were created in response to inquires from data users, whose most frequent questions have concerned either crash frequencies or rates (per MVMT) for one or more of these roadway classes. The accuracy and completeness of the file was again assessed through conversations with Minnesota staff, a series of single-variable tabulations for 30 key variables which are compared across years each time a new file is received, and past HSIS analyses with the data. Minnesota staff feels that, in general, the updating system and the quality of the data are excellent on 12,000 miles of the primary roadway, good on an additional 33,000 miles of state-maintained systems, and adequate or "average" on an additional 90,000 miles of county and local roads.
Single-variable runs were then made for variables related to shoulder type and width, median type and width, access control, surface type and width, divided/undivided designation, functional class, design speed, and urban/rural coding. With few exceptions, the runs indicated very low percentages of "unknown" or "not applicable" codes. Two variables related to "design speed" and "storm sewers" have very high proportions of unknowns. As expected, since they only relate to the approximately two percent of the mileage that is on divided highways, variables related to "Road 2" and those related to medians are characterized by very high proportions of "not applicable." Finally, variables related to left and right shoulder type and width and surface type and width for Road 1 all contain approximately 12 percent of "not applicable" values in the 1990 and earlier files, and approximately 5 percent in the later files. Further conversations with Minnesota staff and computer runs revealed that in most cases, "not applicable" actually means "not coded". However, both information from Minnesota and a cross-tabulation of two of the key variables (shoulder type and surface type) with the variable "road system" in the 1987 file indicated that approximately 92% of these "not applicable (not coded)" sections were on the lower-order township or municipal roadways. All the higher order routes were coded a very high proportion of the time.
With respect to data accuracy, cross checks of the similar variables on the file such as shoulder width and type on different sides of the roadway, pavement type on the divided sections of highway, and others indicated quite consistent data across the variables once the uncoded values were removed. Thus, the file appears accurate, as would be expected from the continuous update procedures in place.
Finally, there is the remaining issue of how to handle the linkage of accidents with divided roadways where the Roadlog information is divided into "roads 1 and 2". Unfortunately, because there is no information on the accident report related to "road 1 or 2", there is no simple way of linking a given crash with the proper piece of pavement. As part of their merging system, Minnesota has attempted to develop some logic for such an assignment based on the direction of travel from the crash form and the mileposting direction from the Roadlog file. However, they are not satisfied that even their best attempt at such logic is accurately assigning the accidents.
We further examined this issue by printing out 200 records related to divided highways in the 1987 file and compared the individual variables for road 1 with road 2 which are related to right shoulder width, right shoulder type, surface width, surface type, left shoulder width, left shoulder type, and the presence or absence of curbs on one or both sides of the roadway. The question being examined here was whether or not there were significant differences between, say, the right shoulder width or type on road 1 versus the same variable for road 2. If little difference is found, it would be possible to simply link any accident occurring on a divided highway section with the characteristics of road 1.
The analysis indicated very little difference between most of the variables on the two roads. Right and left shoulder type, shoulder width, and curb presence on the two roads "disagreed" in only 1 - 4 percent of the cases. The only major area of disagreement was in the variable related to "surface width" for the two roads, where differences were noted in 26 (13%) of the records. Of the 26 disagreements, three surface widths disagreed by two feet, five disagreed by 3-5 feet, 13 disagreed by 10-14 feet (an additional lane), and 5 disagreed by 15 to 20 feet.
Based on these findings, we suggest that two options exist for the analyst in future efforts. First, in all cases where the "divided and one-way code" indicates a "divided rd1 and rd2," programs could be developed to check for differences between road 1 and road 2 values for the variables in question, and records could be dropped from the analysis where differences exist. Or second, for all variables except surface width, the analyst could simply link accidents on divided roadways with "road 1" data. We feel that this second option is quite defensible given the low "disagreement rate" (which would most likely be lower than the error rate related to crash data). With respect to surface width, we suggest that the disagreeing records be dropped from the analysis since there is no good way to accurately link accidents with the appropriate surface width.
Finally, while the basic Roadlog File described above does not contain data on horizontal or vertical alignment, we note that under a separate FHWA contract, alignment data were collected on a sample of approximately 700 miles of two-lane rural paved roads in Minnesota. These data can be made available by the HSIS staff if needed in research projects.
The Traffic File sent by MnDOT contains information related to AADT data for all roadway sections across the state. For ease of analysis, HSIS programs link these data with the Roadlog file, producing an estimated AADT for each homogeneous section in that file. Details of this linkage process are at the end of this section.
The traffic information is manually derived from sample and continuous counts taken at temporary and permanent count stations throughout the State. It contains total AADT's and AADT's for heavy commercial vehicles which are defined as vehicles with two axles and six tires or larger.
Like other states, Minnesota develops traffic volume estimates based on automatic traffic recorder stations (ATR's) and short-term (48-hour) "coverage" counts. There are approximately 120 ATR's which count traffic 24 hours per day, 365 days per year across the various roadway types. These are located on all classes of both rural and urban highway, with approximately 55% of the locations being on urban roadways and 45% on rural roadways.
In addition, there are approximately 34,000 coverage (temporary) count locations across the State where 48-hour counts are made. Approximately 12,000 of these locations are covered each year. For the trunk highway system (including Interstate roads), these counts are made on a two-year cycle, as are counts on roads within the Twin Cities Metro Area. For the lower-order County State-Aid Highways and the Municipal State-Aid System outside the Twin Cities Metro Area, the counts are made on a four-year cycle.
The seasonal adjustment factor for a given coverage count is based on counts made at ATR's which are similar to the coverage count location. Here, ATR's are grouped into the following classifications:
Outside (i.e., Non-Metropolitan area)
Metropolitan Area
Seasonal adjustment factors, based on the data for the previous three years, are developed for each classification and are applied to all coverage counts collected at locations within that classification.
For the "non-count" years, a growth factor is applied to the previous year's data based on changes in counts at the ATR stations located on the same functional class of roadway. When new data are available at the end of the next count cycle, these data for the interim, non-count years are readjusted to represent the average of prior and subsequent count years (e.g., a 1987 "non-count" year estimate based on the growth factor would be readjusted to represent the average of 1986 and 1988 counts at that location as soon as the 1988 count year is completed).
In developing AADT estimates for each section of roadway, there are sometimes road sections with no historical count data (e.g., lower order local facilities including township roadways and local streets). In these cases, an original "baseline" estimate is based on ATR counts on lowest order roadways with the lowest counted volumes. Growth factors for these uncounted sections are also based on this same ATR group.
MnDOT also collects vehicle classification counts at about 300 sites per year. These are 16-hour (e.g., 6 AM to 10 PM) manual classification counts usually over two different days. In addition, portable vehicle classifiers are deployed to collect 48-hour data. Currently, there is no program to seasonally adjust the classification counts. There are an additional 25 Weigh-in-Motion stations statewide that collect classification data. However, these data are used less than the manual classification counts.
The new count data are placed in the Traffic file within the first six months of the subsequent calendar year. While the Traffic File can also be thought of as a "section" file (with a specified AADT at the beginning count station being assumed constant over the entire section), it differs from the Roadlog File to which it will often be merged in that the beginning and end points (termini) are often located at different points on the roadway. The linking variables are again the route system/route number/reference point (milepost).
There are approximately 208,000 records on the file, but these do not represent a one-to-one match with the 220,000 "true" records on the Roadlog file. Often there are Roadlog sections with multiple Traffic File records (i.e., multiple count stations), and often there are Roadlog sections with no Traffic File records (i.e., corresponding count stations) located within the section.
Each raw file record contains up to 30 years of AADT information (with the related year "attached"). Thus, to determine the average AADT for a given year for a series of sections on a given route, (1) the traffic section reference points must be matched with the appropriate Roadlog sections by comparing the reference point with the beginning and ending milepoint on Roadlog sections (with the ending milepoint being "assigned" as being equal to the beginning milepoint on the succeeding section), (2) the appropriate yearly AADT for each contained Traffic file record must be extracted, and (3) the counts must be averaged for sections where multiple Traffic file records exist. If no Traffic file record exists for a given Roadlog section, then the section AADT is assumed to be equal to the AADT at the previous (upstream) traffic section on the same route. (This is the assumption made by Minnesota and by HSRC programs. However, other procedures could be followed in calculating AADT if felt to be more appropriate for a given research question.) Any AADT assignment program developed must not carry over counts from one route to another, a mistake that can easily be made since the Roadlog File is a continuous file in route order. Obviously, averaging traffic over more than one year will require additional programming.
Currently, there are two HSIS SAS-formatted Traffic Files -- one developed for 1987 and earlier data, and one containing data for only 1988 and 1989. Again, please note that traffic data were merged with the Roadlog File for years 1989, 1990-1992, 1994-1996, and 1998-2005. The Traffic File still remains a separate file on the HSIS system for years 1987 thru 1989. It is no longer available as a separate file on the HSIS system after 1989.
The first (1987) Traffic File is similar to the raw file in that it contains up to ten years of data with 1987 counts being the most recent data. The second (1988-89) file contains only counts for 1988 and 1989. Each record on the file contains information on traffic counts for one year for a given location. To combine across years for a given counter location, records with the same location information can be merged.
As noted above, to make the AADT information even more easily usable in subsequent analyses, HSRC developed a linking program which links the basic AADT information from the SAS Traffic File with the Roadlog file to produce a separate single "Average AADT" variable for each Roadlog section on each Roadlog file. Where necessary, averaging across traffic sections in a given Roadlog section for a given year, and "carrying down" AADT information from the prior record has been done in this linkage program. The 1988-89 traffic data are linked with the 1989 Roadlog file for use with the 1988-89 accidents. In this case, the AADT variable on the 1989 Roadlog file represents an average AADT over that two-year time period. Different AADT's (say for individual accident years) could be developed by modifying the existing computer program.
Since it is not possible to perform an independent "check" of the accuracy of the AADT information, it is assumed that the procedure in place in Minnesota to monitor count stations and update the file provides adequate information. As indicated above, these are felt to be excellent data for the trunkline system where they are updated on a two-year cycle. There is also fairly good data for the county state-aid systems which are generally updated on a four-year cycle.
As noted above, the Interchange/Intersection File is a file of intersections on major roadways that are maintained by the eight different MnDOT Districts across the state. The file will contain intersections of US/US, US/state, and all interchanges on the Interstate roadways. The files currently available include years 1987 and individual files for years 1990-2005. There are individual records in the file for approximately 2,500 interchanges, 26,600 intersections, and 3,900 intersections within interchanges.
Conversations with a limited sample of current district traffic engineers and a retired State Traffic Engineer who helped "design" the system indicate that while the criteria for choosing the "original" intersections may have differed slightly from district-to-district (since no criteria were actually defined), the overall purpose for building the file was to allow for subsequent identification of high-accident locations. Thus, originally, all intersections which were to be examined for accident problems were included, which appears to mean all "major" intersections, regardless of past accident problems. Once on the file, an intersection has remained so that its accident frequency and rate can be examined each subsequent year. (Thus, "low accident sites" for a given year are not dropped from the file.) In summary, while not a "random" sample of major intersections, the original (or subsequent) intersection choice does not seem to greatly bias the file for analysis purposes.
There is no regular system of update, but changes are noted when they are found. One district now seems to have well updated data while the other districts may or may not have data updated on a regular basis. Using this file, accident rates for the intersections can be developed. It is noted that the file is characterized by intersections of one roadway with all of the roads that cross it. Since location information is present for all crossing routes, it is possible to link all routes with the Roadlog file information.
As noted above, there are approximately 2,500 interchange records within the file. Each interchange will have a primary record, and for some interchange types (primarily diamond interchanges), there will be additional supplemental records on each "intersection within interchange." There are approximately 3,900 of these supplemental records in the file. These supplemental records will also contain additional information the type of interchange element (e.g., mainline between ramps, exit ramp, intersection at ramp terminal on crossing roadway, etc.) More detail on the coding is provided under ELEM_NBR in the later format section.
Each SAS intersection record in the HSIS file contains three different types of "subrecords": (1) a set of "general" variables describing the entire intersection (e.g., intersection type), (2) a set of "reference" variables for each of six possible incoming routes, referred to as "segment" variables, and (3) a set of variables for up to two "legs" (or approaches) per route (e.g. approach AADT, speed limit).
Because of the complexity of the file, there will be times when the analyst wishes to look at routes rather than on individual intersection "legs." For this reason, HSIS staffs have developed programs which will produce a modified file named the Intersection Route File. This file consists of a record for each route of the intersecting routes of an intersection. Many of the variables are still the same as in the basic Intersection File. The major difference in this file is that the variables represent descriptions for each route. The "In" and "Out" descriptors denote the incoming and outgoing routes of each leg. This file format can be produced for the user by HSIS staff on request.
The completeness and accuracy of the data in these files were again assessed through the above-noted conversations with Minnesota system designers and users, examination of single-variable tabulations for key variables, HSIS analyses, and limited cross-checking of data in the files versus videologs of intersections found in the Minnesota videodisk system.
Examination of the single-variable tables indicates that while there is a higher proportion of uncoded data than in other major files, adequate coding exists for most variables. It is noted that there is a significant amount of missing AADT data (10 to 30 percent) in the "segment 2, leg 2" records -- records usually related to the second (opposing) approach of the minor crossing roadway. AADT's are usually present for both legs of the major roadway and for the first leg of the minor roadway. One solution that has been used thus far is to assume that the missing leg 2 AADT is equal to the leg 1 AADT on the same route.
More importantly, we have determined from analyses and conversations with MnDOT staff that the majority of the AADT data in the Intersection/Interchange file are not current -- they do not match the year of the file. The user can determine which year the AADT was collected for each leg from the "AADT Year" variable attached to each leg. However, we have found that the "AADT Year" will very seldom be the current (file) year, and that the year of the AADT count can be different for different legs of the same intersection. For major routes, more recent AADT information can be extracted from the Roadlog File by linking the intersection leg with the appropriate roadway segment in that file. Unfortunately, we cannot suggest a method for "updating" the AADT data to later years for crossing roadways not found on the Roadlog file. Since multiple year data are often shown in the file, the user may be able to develop a "trend-related update", but we cannot assure that the estimates will be correct.
With this AADT exception, the file is complete in that there are few true "missing" or miscoded values. Other variables seem to be updated in a more timely manner. There is large number of "not applicable" codes within many of the variable, but this appears to result from the fact that some of the variables are specific to special types of intersections (e.g., intersections within interchanges, signalized intersections, and pedestrian crossings).
The preliminary HSIS analyses have indicated some additional problems with a limited number of variables. As with all files, incomplete coding or apparent inaccuracies are detailed in a "NOTE" under the pertinent variable in the later SAS format section.
In a final check of accuracy, the descriptive variables for a significant sample of the intersections on the file were manually compared to a videotaped picture of the intersection. The picture was located in the Minnesota videodisk system which covers all major Minnesota routes, and which is available at FHWA for research efforts. In general, it was found that the data on the Intersection File are accurate and reliable for interchanges, signalized intersections, and major unsignalized intersections (e.g., unsignalized intersections with turn lanes on major routes). The comparison pointed out that there are cases in which more than one intersection is located on the File at the same milepoint. The videolog indicated that this usually happens when there are intersections within an interchange, as would be the case with diamond interchanges. This situation can be detected using the TYPE variable.
In general, while not perfect, the Intersection/Interchange File is clearly adequate for analysis purposes. The only major problem is with the timeliness of the AADT data.
According to MnDOT, HSRC was to receive "linkable" accident data. This was true almost all of the time. However, during later merging efforts by HSRC programmers, it was discovered that some route numbers on the accident file did not exist on the Roadlog file. MnDOT confirmed that they had only recently discovered the problem and that it was unlikely that they would be able to restore the correct location of those accidents. This problem represented less than 1% of the total accident file. Minnesota indicated that the "bad" accident routes were likely to have route numbers with the last three or four digits repeating (i.e., 190008888). HSRC runs confirmed this in many, but not all, cases.
As noted above, the accident data are subdivided into three subfiles -- accident, vehicle and occupant. These subfiles can be linked together using the "case number" variable (i.e., CASENO) present in each of the three files. When linking the occupant subfile, the additional linking variable "vehicle number" (i.e., VEHNO) must match so that the occupants are associated with the vehicle in which they were traveling. To link the Vehicle subfile with the Accident alone, first sort both subfiles by case number. To link the Occupant file with the other two subfiles, first sort both the Vehicle subfile and Occupant subfile by case number and vehicle number. Next sort the Accident subfile by case number. Alternatively, the separate subfiles can blinked by specifying an SQL JOIN operation with the constraining condition that case number and vehicle number from each table are equal. SQL processing does not require the data to be presorted and the output will not be in any particular sort order unless ORDER BY is specified.
The Accident subfile can then be linked with the Roadlog File using information related to route system, route number, and milepost on the route. The actual linkage variables on the Accident file which are used in the merging operation are RTSYSNBR (a combination of route system and route number) and MILEPOST. The linkage variables on the Roadlog File are BEGMP, ENDMP, and RTSYSNBR.
To prepare the Accident subfile for linking with the Roadlog File using a SAS data step process, the analyst must sort both the Accident and the Roadway File into location order by RTSYSNBR and MILEPOST on the Accident file and by RTSYSNBR and BEGMP on the Roadlog File. Similar sorts would be done with other files to be merged. For the alternative SQL join, the analyst must specify an exact match on RTSYSNBR from both files and a range match where MILEPOST occurs between BEGMP and ENDMP
To link the Accident File with the Intersection/Interchange File requires similar logic, but somewhat more file manipulation. Again, the basic linkage variables are route system, route number, and milepost.
For the primary route within the Intersection/Interchange File (i.e., the initial reference route identified in the "general" variables), route system, and route number have already been combined into INT_SYNB and reference point information has been converted to MILEPOST. Thus, the linkage is similar to the Roadlog file linkage. However, matching crashes (or Roadlog information) to the individual Asegment@ variables which define all possible crossing routes is somewhat more complex. Here, the Intersection File does not contain the combined route/system variable (INT_SYNB), so the two individual variables (RTE_SYS, RTE_NBR) must be combined before matching. In addition, the milepost variables must be derived from the "Reference Point" variable (REF_PNT). The REF_PNT variable consists of 10 bytes (i.e., 050+00.900). The first three bytes is the "reference post" and the last three bytes is the offset from the reference post. To develop the milepost variable, bytes 5-6 will need to be removed (i.e., 50.900). Once these new variables are formed, the same linking logic described above can be used. Note that programs to carry out these conversions and file linkages have been developed by HSIS staff and can be obtained from the staff when needed.
Finally, where appropriate and possible, a format which defines categories within a given variable has been developed for HSIS SAS variables. These categories are shown in the pages below. If you are a SAS user and wish to receive a formatting program which includes these SAS formats (with linkage to the pertinent variable name), please request these from the HSIS staff who provides the data file to you.
Dave Engstrom (651-234-7016) – Mr. Engstrom is our main contact within the state of Minnesota when questions arise concerning the crash, intersection, and videolog data in the Transportation Information System (TIS). He is the Traffic Safety Engineer for the Minnesota DOT.
Matt Koukol (651-366-3859) – Mr. Koukol is the primary contact within Minnesota DOT regarding the traffic and roadway data, as well as data acquisition.
| SAS VARIABLE NAME | DESCRIPTION | SAS VARIABLE FILE | FORMAT TYPE | PAGE NO. |
|---|---|---|---|---|
| AADT | CALCULATED AVERAGE AADT | Roadlog | NUM | 83 |
| AADT111 | SEGMENT 1, LEG 1, YEAR 1 AADT | Intersct-chg | NUM | 115 |
| AADT112 | SEGMENT 1, LEG 1, YEAR 2 AADT | Intersct-chg | NUM | 116 |
| AADT113 | SEGMENT 1, LEG 1, YEAR 3 AADT | Intersct-chg | NUM | 116 |
| AADT114 | SEGMENT 1, LEG 1, YEAR 4 AADT | Intersct-chg | NUM | 116 |
| AADT115 | SEGMENT 1, LEG 1, YEAR 5 AADT | Intersct-chg | NUM | 116 |
| ACC_DATE | DATE ACCIDENT OCCURRED | Accident | CHA(8) | 43 |
| ACCDIGM | DIAGRAM OF ACCIDENT CODE | Accident | NUM | 43 |
| ACCESS | CONTROL OF ACCESS | Roadlog | NUM | 83 |
| ACCTYPE | TYPE OF ACCIDENT | Accident | NUM | 43 |
| ACCYR | YEAR ACCIDENT OCCURRED | Accident | CHA(4) | 44 |
| ADLN_RD1 | ADDITIONAL LANES - ROAD 1 | Roadlog | CHA(1) | 83 |
| ADLN_RD2 | ADDITIONAL LANES - ROAD 2 | Roadlog | CHA(1) | 83 |
| ADTYR111 | SEGMENT 1, LEG 1, YEAR 1 | Intersct-chg | CHA(2) | 115 |
| ADTYR112 | SEGMENT 1, LEG 1, YEAR 2 | Intersct-chg | CHA(2) | 116 |
| ADTYR113 | SEGMENT 1, LEG 1, YEAR 3 | Intersct-chg | CHA(2) | 116 |
| ADTYR114 | SEGMENT 1, LEG 1, YEAR 4 | Intersct-chg | NUM | 116 |
| ADTYR115 | SEGMENT 1, LEG 1, YEAR 5 | Intersct-chg | CHA(2) | 116 |
| AGE | AGE OF INJURED/KILLED | Occupant | NUM | 72 |
| AIRBAG | AIRBAG DEPLOYED | Occupant | CHA(2) | 72 |
| ALCOHOL_RESULT | BLOOD ALCOHOL TEST RESULT | Occupant | CHA(2) | 72 |
| ALCOHOL_TEST | BLOOD ALCOHOL TEST PERFORMANCE | Occupant | CHA(1) | 72 |
| AMBL_NBR | AMBULANCE NUMBER | Accident | CHA(6) | 44 |
| AP_SPD11 | SEGMENT 1, LEG 1, APPROACH SPEED LIMIT | Intersct-chg | NUM | 117 |
| APCNTL11 | SEGMENT 1, LEG 1, APPROACH TRAFFIC CONTROL | Intersct-chg | NUM | 117 |
| BAS_TKR1 | BASE THICKNESS - ROAD 1 | Roadlog | CHA(3) | 84 |
| BEGMP | CALCULATED BEGIN MILEPOST | Roadlog | NUM | 84 |
| BIRTH_DT | BIRTHDAY | Occupant | CHA(8) | 73 |
| BRK_CD | BREAK CODE | Roadlog | NUM | 84 |
| CASENO | ACCIDENT NUMBER | Accident | CHA(11) | 44 |
| CASENO | ACCIDENT NUMBER | Occupant | CHA(11) | 73 |
| CASENO | ACCIDENT NUMBER CODE | Vehicle | CHA(11) | 58 |
| CNTL_CAT | CENTRAL OFFICE CATEGORY | Intersct-chg | CHA(2) | 107 |
| COMM_ADT | CALCULATED AVERAGE COMMERCIAL AADT | Roadlog | NUM | 84 |
| CONTRIB1 | FIRST CONTRIBUTING FACTOR | Vehicle | NUM | 58 |
| CONTRIB2 | SECOND CONTRIBUTING FACTOR | Vehicle | NUM | 58 |
| CORN_RPT | CORONER REPORT RECORD | Occupant | CHA(1) | 73 |
| COUNTY | COUNTY | Accident | NUM | 45 |
| COUNTY | COUNTY | Roadlog | NUM | 85 |
| CURB1 | CURBS - ROAD 1 | Roadlog | CHA(1) | 85 |
| CURB2 | CURBS - ROAD 2 | Roadlog | CHA(1) | 85 |
| SAS VARIABLE NAME | DESCRIPTION | SAS VARIABLE FILE | FORMAT TYPE | PAGE NO. |
|---|---|---|---|---|
| DAMSEV | VEHICLE DAMAGE SEVERITY | Vehicle | CHA(1) | 59 |
| DESC_ | INTERSECTION DESCRIPTION | Intersct-chg | NUM | 104 |
| DIR_CDE | DIRECTION CODE | Roadlog | CHA(2) | 85 |
| DIRECT11 | SEGMENT 1, LEG 1 DIRECTION | Intersct-chg | NUM | 115 |
| DIST_CAT | CATEGORY ASSIGNED BY DISTRICT | Intersct-chg | CHA(2) | 107 |
| DIV_CODE | ROAD DESIGN | Accident | NUM | 45 |
| DL_CLASS | DRIVER LICENSE CLASS | Occupant | CHA(1) | 73 |
| DL_STATE | DRIVER LICENSE STATE | Occupant | CHA(2) | 73 |
| DL_WITHD | DRIVER LICENSE WITHDRAWAL | Occupant | CHA(1) | 74 |
| DRIV_REC | DRIVER RECOMMENDATION | Occupant | CHA(2) | 74 |
| DRUG_TEST | DRUG TEST PERFORMED | Occupant | CHA(1) | 74 |
| DRV_AGE | AGE OF DRIVER | Vehicle | NUM | 59 |
| DRV_INJ | DRIVER INJURY | Vehicle | CHA(1) | 59 |
| DRV_SEX | SEX OF DRIVER | Vehicle | CHA(1) | 59 |
| EFEC_DTE | DATE OF ACCIDENT GEOCODING | Intersct-chg | NUM | 108 |
| EJECT | EJECTION FROM VEHICLE | Occupant | NUM | 74 |
| ELEM_NBR | INTERCHANGE ELEMENT CODE | Intersct-chg | CHA(3) | 103 |
| ENDMP | CALCULATED ENDING MILEPOST | Intersct-chg | NUM | 103 |
| ENDMP | CALCULATED ENDING MILEPOST | Roadlog | NUM | 85 |
| EQUIP_TYPE | TYPE OF SAFETY EQUIPMENT | Occupant | CHA(2) | 74 |
| EVENT1 | SEQUENCE OF EVENT -1 | Vehicle | CHA(2) | 60 |
| EVENT2 | SEQUENCE OF EVENT -2 | Vehicle | CHA(2) | 60 |
| EVENT3 | SEQUENCE OF EVENT -3 | Vehicle | CHA(2) | 60 |
| EVENT4 | SEQUENCE OF EVENT -4 | Vehicle | CHA(2) | 60 |
| FAT_NUM | FATALITY NUMBER | Occupant | CHA(4) | 75 |
| FATLDATE | FATALITY DATE | Occupant | NUM | 75 |
| FED_AID | FEDERAL AID SYSTEM | Roadlog | CHA(1) | 85 |
| FED_SYSD | FEDERAL AID SYSTEM - DESIGNATED | Roadlog | CHA(1) | 86 |
| FED_SYSR | FEDERAL AID SYSTEM - REGULAR | Roadlog | CHA(1) | 86 |
| FIRE | FIRE IN VEHICLE | Vehicle | CHA(1) | 61 |
| FUNC_CLS | FUNCTIONAL CLASS | Roadlog | NUM | 86 |
| GEN_ENIV | GENERAL ENVIRONMENT | Intersct-chg | NUM | 107 |
| H_COUNT | NUMBER OF COUNT STATIONS PER SECTION | Roadlog | NUM | 86 |
| HAZMAT | HAZARDOUS MATERIAL CARRIED | Accident | CHA(1) | 45 |
| HAZMTL | VEHICLE CARRYING HAZARDOUS MATERIAL | Vehicle | CHA(1) | 61 |
| HIT_RUN | HIT AND RUN | Accident | CHA(1) | 45 |
| HOSP | INJURED TAKEN TO HOSPITAL | Occupant | CHA(1) | 75 |
| HOSPTRAN | TRANSPORTED TO HOSPITAL METHOD | Occupant | CHA(1) | 75 |
| HOUR | HOUR ACCIDENT OCCURRED | Accident | NUM | 45 |
| INJ | INJURY SEVERITY | Occupant | CHA(1) | 75 |
| INT_SYNB | COMBINED RTE_SYS/RTE_NBR | Intersct-chg | CHA(11) | 102 |
| INT_TYPE | INTERSECTION TYPE | Intersct-chg | NUM | 103 |
| INTE_CAT | INTERSECTION CATEGORY | Roadlog | NUM | 87 |
| INTERCH | INTERCHANGE ELEMENT CODE | Accident | CHA(3) | 46 |
| SAS VARIABLE NAME | DESCRIPTION | SAS VARIABLE FILE | FORMAT TYPE | PAGE NO. |
|---|---|---|---|---|
| INTRANSPORT | WAS VEHICLE IN TRANSPORT | Vehicle | CHA(1) | 61 |
| INV_DTE | INVENTORY DATE | Roadlog | CHA(8) | 87 |
| LANEWID | LANE WIDTH | Roadlog | NUM | 87 |
| LEGNBR11 | SEGMENT 1, LEG NUMBER 1 | Intersct-chg | NUM | 115 |
| LICTYPE | VALID DRIVER LICENSE | Vehicle | CHA(1) | 61 |
| LIGHT | LIGHT CONDITIONS | Accident | NUM | 46 |
| LIS_RSTR | COMPLIANCE WITH LICENSE RESTRICTIONS | Occupant | CHA(1) | 76 |
| LOC_BIKE | LOCATION OF PEDESTRIAN/BIKE | Accident | NUM | 46 |
| ACCIDENT | ||||
| LOC_HARM | LOCATION OF FIRST HARMFUL | Accident | NUM | 46 |
| EVENT | ||||
| LOC_NARR | LOCATION DESCRIPTION | Accident | CHA(50) | 47 |
| LOC_TYPE | RELATION TO INTERSECTION | Accident | NUM | 47 |
| LOC_WRK_ZNE | LOCATION OF ACC IN WORKZONE | Accident | CHA(2) | 47 |
| LOCN_REL | LOCATION RELIABILITY | Accident | CHA(1) | 47 |
| LOLIMT1 | SEGMENT 1 LOWER LIMIT | Intersct-chg | NUM | 112 |
| LSHL_TY2 | LEFT SHOULDER TYPE - ROAD 2 | Roadlog | CHA(2) | 88 |
| LSHL_TYP | LEFT SHOULDER TYPE - ROAD 1 | Roadlog | CHA(2) | 88 |
| LSHL_WD2 | LEFT SHOULDER WIDTH - ROAD 2 | Roadlog | CHA(2) | 89 |
| LSHLDWID | LEFT SHOULDER WIDTH - ROAD 1 | Roadlog | CHA(2) | 89 |
| MAKE | MAKE OF VEHICLE MATERIAL | Vehicle | CHA(4) | 62 |
| MCAXLDN | MOTOR CARRIER AXLES DOWN | Vehicle | CHA(2) | 62 |
| MCAXLUUP | MOTOR CARRIER AXLES UP | Vehicle | CHA(2) | 62 |
| MCBDYTYP | MOTOR CARRIER BODY TYPE | Vehicle | CHA(2) | 62 |
| MCGVWRCD | MOTOR GROSS VEHICLE WEIGHT CODE | Vehicle | CHA(2) | 62 |
| MCHZPLAC | MOTOR HAZARDOUS MATERIAL PLACARD FLAG | Vehicle | CHA(1) | 63 |
| MCSOURCE | SOURCE OF IDENTIFICATION | Vehicle | CHA(2) | 63 |
| MCTRHTCH | MOTOR TRAILER HITCH CODE | Vehicle | CHA(2) | 63 |
| MED_TYPE | MEDIAN TYPE | Roadlog | CHA(1) | 89 |
| MEDWID | MEDIAN WIDTH (IN FEET) | Roadlog | CHA(2) | 90 |
| MILEPOST | MODIFIED REFERENCE POINT | Accident | NUM | 48 |
| MILEPOST | MODIFIED REFERENCE POINT LOCATION | Intersct-chg | NUM | 102 |
| MISCACT1 | ACTION PRIOR TO ACCIDENT | Vehicle | NUM | 63 |
| MODEL | MOTOR MODEL | Vehicle | CHA(2) | 64 |
| MOST_EVENT | MOST HARMFUL EVENT | Vehicle | CHA(2) | 65 |
| MVCLASS | MOTOR CLASS | Vehicle | CHA(2) | 66 |
| MVMT | MILLION VEHICLE MILES TRAVELED | Roadlog | NUM | 90 |
| MVTYPE | MOTOR TYPE | Vehicle | CHA(2) | 66 |
| NBR_LEG1 | NUMBER OF LEGS ON SEGMENT 1 | Intersct-chg | NUM | 113 |
| NBR_LEGS | NUMBER OF LEGS INTO INTERSECTION | Intersct-chg | NUM | 108 |
| SAS VARIABLE NAME | DESCRIPTION | SAS VARIABLE FILE | FORMAT TYPE | PAGE NO. |
|---|---|---|---|---|
| NBR_RTES | NUMBER OF ROUTES INTO INTERSECTION | Intersct-chg | NUM | 108 |
| NBRVOL | TOTAL NUMBER OF TRAFFIC VOLUME COUNTS | Roadlog | NUM | 90 |
| NBRVOLB | NUMBER OF BLANK TRAFFIC VOLUME COUNTS | Roadlog | NUM | 90 |
| NBRVOLF | NUMBER OF FULL TRAFFIC VOLUME COUNTS | Roadlog | NUM | 90 |
| NO_LANE1 | NUMBER THROUGH LANES TOWARDS INCREASING MILEPOINTS | Roadlog | CHA(1) | 90 |
| NO_LANE2 | NUMBER THROUGH LANES TOWARDS DECREASING MILEPOINTS | Roadlog | CHA(1) | 90 |
| NO_LANES | TOTAL NUMBER OF LANES | Roadlog | NUM | 91 |
| NUMOCCS | NUMBER OF OCCUPANTS | Vehicle | NUM | 66 |
| NUMVEHS | NUMBER OF VEHICLES INVOLVED | Accident | NUM | 48 |
| OBJECT1 | FIXED OBJECT STRUCK | Accident | NUM | 48 |
| OFF_TYPE | TYPE OF INVESTIGATING OFFICER | Accident | NUM | 48 |
| ON_BRDG | ACCIDENT OCCURRED ON BRIDGE | Accident | CHA(1) | 49 |
| ONEWAY | DIVIDED AND ONE-WAY CODE | Roadlog | CHA(1) | 91 |
| PARKING1 | PARKING ON ROAD 1 | Roadlog | CHA(1) | 91 |
| PARKING2 | PARKING ON ROAD 2 | Roadlog | CHA(1) | 91 |
| PHYSCOND | PHYSICAL CONDITION OF DRIVER | Vehicle | NUM | 66 |
| PHYSCOND | PHYSICAL CONDITION | Occupant | NUM | 76 |
| POP_FROM_CITY | POPULATION OF CITY | Accident | NUM | 49 |
| POP_FROM_COUNTY | POPULATION OF COUNTY | Accident | NUM | 49 |
| POP_GRP | URBAN/RURAL POPULATION CODES | Accident | NUM | 49 |
| PUBDMG | PUBLIC PROPERTY DAMAGE | Accident | CHA(1) | 50 |
| RAIL_NBR | RAILROAD CROSSING NUMBER | Intersct-chg | CHA(8) | 104 |
| RD_CHAR1 | ROAD CHARACTERISTICS | Accident | NUM | 50 |
| RDESC1 | ROAD DESCRIPTION | Intersct-chg | NUM | 112 |
| RDSURF | ROAD SURFACE CONDITIONS | Accident | NUM | 50 |
| RDWORK | ROAD WORK BEING PERFORMED | Accident | NUM | 50 |
| RDWY_LGH | ROADWAY LIGHTING | Intersct-chg | NUM | 107 |
| REF_PNT | REFERENCE POINT | Intersct-chg | CHA(10) | 103 |
| REF_PST | REFERENCE POST | Roadlog | CHA(3) | 92 |
| REFPNT1 | REFERENCE POINT-ROUTE 1 | Intersct-chg | CHA(10) | 111 |
| REMARK | REMARKS - TYPE OF RECORD | Roadlog | CHA(2) | 92 |
| RES_CNTY | RESIDENCE COUNTY | Occupant | NUM | 77 |
| REST1 | SAFETY EQUIPMENT USED | Occupant | CHA(1) | 77 |
| RODWYCLS | ROADWAY CLASSIFICATION | Accident | CHA(2) | 51 |
| RODWYCLS | ROADWAY CLASSIFICATION | Roadlog | CHA(2) | 92 |
| ROW | RIGHT OF WAY WIDTH | Roadlog | CHA(3) | 92 |
| RSHL_TY2 | RIGHT SHOULDER TYPE - ROAD 2 | Roadlog | CHA(2) | 93 |
| RSHL_TYP | RIGHT SHOULDER TYPE - ROAD 1 | Roadlog | CHA(2) | 93 |
| RSHL_WD2 | RIGHT SHOULDER WIDTH - ROAD 2 | Roadlog | CHA(2) | 94 |
| RSHLDWID | RIGHT SHOULDER WIDTH - ROAD 1 | Roadlog | CHA(2) | 94 |
| RTE_NBR | ROUTE NUMBER | Accident | CHA(9) | 51 |
| RTE_NBR | ROUTE NUMBER | Intersct-chg | CHA(9) | 102 |
| SAS VARIABLE NAME | DESCRIPTION | SAS VARIABLE FILE | FORMAT TYPE | PAGE NO. |
|---|---|---|---|---|
| RTE_NBR | ROUTE NUMBER | Roadlog | CHA(9) | 94 |
| RTE_SYS | ROUTE SYSTEM | Intersct-chg | CHA(2) | 102 |
| RTE_SYS | ROUTE SYSTEM | Accident | CHA(2) | 51 |
| RTE_SYS | ROUTE SYSTEM | Roadlog | CHA(2) | 95 |
| RTENBR1 | ROUTE NUMBER - ROUTE 1 | Intersct-chg | CHA(9) | 111 |
| RTESYS1 | ROUTE SYSTEM - ROUTE 1 | Intersct-chg | CHA(2) | 111 |
| RTSYSNBR | COMBINED ROUTE SYSTEM/ROUTE NUMBER | Accident | CHA(11) | 52 |
| RTSYSNBR | COMBINED ROUTE SYSTEM/ROUTE NUMBER | Roadlog | CHA(11) | 95 |
| SCHLBUS | SCHOOL BUS INVOLVED ACCIDENT | Accident | CHA(1) | 52 |
| SEATPOS | POSITION IN VEHICLE | Occupant | NUM | 78 |
| SEG_LNG | CALCULATED SECTION LENGTH | Roadlog | NUM | 95 |
| SERIES | SERIES OF VEHICLE | Vehicle | CHA(3) | 66 |
| SEVERITY | ACCIDENT SEVERITY | Accident | CHA(1) | 52 |
| SEX | SEX OF INJURED/KILLED OCCUPANT | Occupant | CHA(1) | 78 |
| SFTY_CLS | SAFETY IMPROVEMENT CLASSIFICATION | Intersct-chg | CHA(2) | 108 |
| SFTY_IMD | SAFETY IMPROVEMENT DISTRICT | Intersct-chg | CHA(1) | 108 |
| SFTY_IMY | SAFETY IMPROVEMENT YEAR | Intersct-chg | CHA(2) | 107 |
| SFTY_PRJ | SAFETY IMPROVEMENT PROJECT NUMBER | Intersct-chg | CHA(2) | 108 |
| SIDE_WLK | SIDEWALKS | Roadlog | CHA(1) | 95 |
| SIGN_CON | TRAFFIC SIGNALS CONSTRUCTION | Intersct-chg | NUM | 106 |
| SIGN_PED | TRAFFIC SIGNALS PEDESTRIAN SIGNALS | Intersct-chg | NUM | 106 |
| SIGN_PLA | SIGNAL HEAD PLACEMENT | Intersct-chg | NUM | 106 |
| SIGN_PRO | TRAFFIC SIGNALS PROGRESSION | Intersct-chg | NUM | 105 |
| SIGN_TIM | TRAFFIC SIGNALS TIMING | Intersct-chg | NUM | 105 |
| SPEC_ENV | SPECIFIC ENVIRONMENT | Intersct-chg | NUM | 107 |
| SPEED | POSTED SPEED LIMIT | Accident | CHA(2) | 52 |
| STM_SEW | STORM SEWERS | Roadlog | CHA(1) | 96 |
| SUF_TYP1 | SURFACE SPECIFICATION NUMBER - ROAD 1 | Roadlog | CHA(4) | 96 |
| SUF_TYP2 | SURFACE SPECIFICATION NUMBER - ROAD 2 | Roadlog | CHA(4) | 96 |
| SUR_TKR1 | SURFACE THICKNESS – ROAD 1 | Roadlog | CHA(3) | 96 |
| SUR_TKR2 | SURFACE THICKNESS – ROAD 2 | Roadlog | CHA(3) | 96 |
| SURF_TY2 | SURFACE TYPE - ROAD 2 | Roadlog | CHA(2) | 96 |
| SURF_TYP | SURFACE TYPE - ROAD 1 | Roadlog | CHA(2) | 96 |
| SURF_WD2 | SURFACE WIDTH - ROAD 2 (IN FEET) | Roadlog | CHA(2) | 97 |
| SURF_WID | SURFACE WIDTH - ROAD 1 (IN FEET) | Roadlog | CHA(2) | 97 |
| TOT_INJ | NUMBER OF PERSONS INJURED | Accident | NUM | 52 |
| TOT_KILL | NUMBER OF PERSONS KILLED | Accident | NUM | 52 |
| SAS VARIABLE NAME | DESCRIPTION | SAS VARIABLE FILE | FORMAT TYPE | PAGE NO. |
|---|---|---|---|---|
| TOWAWAY | VEHICLE TOWED | Vehicle | CHA(1) | 67 |
| TOWING | TOWING FLAG | Vehicle | CHA(1) | 67 |
| TRAF_DEV | TRAFFIC CONTROL DEVICES | Intersct-chg | NUM | 105 |
| TRAF_PHS | TRAFFIC SIGNALS NUMBER OF PHASES | Intersct-chg | NUM | 106 |
| TRAF_PRE | TRAFFIC SIGNALS PREEMPTION | Intersct-chg | NUM | 106 |
| TRAF_TMF | FLASHING SIGNAL TIME OFF | Intersct-chg | CHA(2) | 106 |
| TRAF_TMO | FLASHING SIGNAL TIME ON | Intersct-chg | CHA(2) | 106 |
| TRAFCNTL | TRAFFIC CONTROL DEVICES | Intersct-chg | NUM | 108 |
| TRF_CNTL | TRAFFIC CONTROL DEVICES | Accident | NUM | 52 |
| TRF_CNTL | TRAFFIC CONTROL DEVICES- REVISED | Intersct-chg | NUM | 105 |
| TRFCNTLW | TRAFFIC CONTROL WORKING | Accident | NUM | 53 |
| TRVL_DIR | TRAVEL DIRECTION | Accident | CHA(1) | 53 |
| TURN_LN | TURNING LANES TOWARD INCREASING MILEPOSTS | Roadlog | CHA(1) | 97 |
| TURN_LN2 | TURNING LANES TOWARD DECREASING MILEPOSTS | Roadlog | CHA(1) | 97 |
| TWNSHIP | TOWNSHIP NUMBER | Accident | NUM | 53 |
| TYPEDESC | INTERSECTION DESCRIPTION- REVISED | Intersct-chg | NUM | 104 |
| UPDATE_ | DATE OF UPDATE | Roadlog | NUM | 98 |
| UPLIMT1 | SEGMENT 1 UPPER LIMIT | Intersct-chg | NUM | 113 |
| URB_MNC | URBAN/MUNICIPAL CODE | Roadlog | NUM | 98 |
| V_DAMAGE | VEHICLE DAMAGE AREA | Vehicle | NUM | 67 |
| VALID_LICENSE | VALID DRIVER LICENSE | Occupant | CHA(2) | 79 |
| VEH_DIR | DIRECTION VEHICLE WAS TRAVELING | Vehicle | NUM | 67 |
| VEH_MOV1 | VEHICLE MOVEMENT | Accident | NUM | 53 |
| VEH_USE | SPECIAL VEHICLE USE | Vehicle | CHA(2) | 68 |
| VEHNO | RELATIVE VEHICLE NUMBER | Vehicle | NUM | 68 |
| VEHNO | VEHICLE OCCUPIED BY INJURED/ KILLED | Occupant | NUM | 79 |
| VEHSTATE | STATE OF VEHICLE REGISTRATION | Vehicle | CHA(2) | 68 |
| VEHTYPE | TYPE OF VEHICLE | Vehicle | NUM | 68 |
| VEHYR | MODEL YEAR OF VEHICLE | Vehicle | CHA(4) | 69 |
| VIOLATIONS | DRIVER CITED FOR VIOLATIONS | Occupant | CHA(1) | 79 |
| VOLGRP | TRAFFIC VOLUME GROUP | Roadlog | CHA(2) | 98 |
| VOLTYP | TRAFFIC VOLUME TYPE | Roadlog | CHA(1) | 98 |
| WAIVED | COMMERCIAL VEHICLE INSPECTION WAIVED | Vehicle | CHA(1) | 69 |
| WAST_MAT | WASTE MATERIAL CARRIED | Accident | CHA(1) | 54 |
| WASTE_MT | VEHICLE CARRYING WASTE MATERIAL | Vehicle | CHA(1) | 70 |
| WEATHER | WEATHER CONDITIONS | Accident | NUM | 55 |
| WEATHER1 | WEATHER CONDITIONS | Accident | NUM | 55 |
| WEATHER2 | WEATHER CONDITIONS | Accident | NUM | 55 |
| WEEKDAY | DAY OF WEEK ACCIDENT OCCURRED | Accident | NUM | 55 |
| WORK_REL | WORK RELATED ACCIDENT | Occupant | CHA(1) | 79 |
| WORK_ZONE | WORKZONE MARKED | Accident | CHA(2) | 55 |
| WRKS_PRESNT | WORKER PRESENT | Accident | CHA(1) | 55 |
| YEAR | YEAR OF TRAFFIC | Roadlog | CHA(4) | 98 |
| SAS VARIABLE NAME | DESCRIPTION | SAS VARIABLE FILE | FORMAT TYPE | PAGE NO. |
|---|---|---|---|---|
| ACC_DATE | DATE ACCIDENT OCCURRED | Accident | CHA(8) | 43 |
| ACCDIGM | DIAGRAM OF ACCIDENT CODE | Accident | NUM | 43 |
| ACCTYPE | TYPE OF ACCIDENT | Accident | NUM | 43 |
| ACCYR | YEAR ACCIDENT OCCURRED | Accident | CHA(4) | 44 |
| AMBL_NBR | AMBULANCE NUMBER | Accident | CHA(6) | 44 |
| CASENO | ACCIDENT NUMBER | Accident | CHA(11) | 44 |
| COUNTY | COUNTY | Accident | NUM | 45 |
| DIV_CODE | ROAD DESIGN | Accident | NUM | 45 |
| HAZMAT | HAZARDOUS MATERIAL CARRIED | Accident | CHA(1) | 45 |
| HIT_RUN | HIT AND RUN | Accident | CHA(1) | 45 |
| HOUR | HOUR ACCIDENT OCCURRED | Accident | NUM | 45 |
| INTERCH | INTERCHANGE ELEMENT CODE | Accident | CHA(3) | 46 |
| LIGHT | LIGHT CONDITIONS | Accident | NUM | 46 |
| LOC_BIKE | LOCATION OF PEDESTRIAN/BIKE ACCIDENT | Accident | NUM | 46 |
| LOC_HARM | LOCATION OF FIRST HARMFUL EVENT | Accident | NUM | 46 |
| LOC_NARR | LOCATION DESCRIPTION | Accident | CHA(50) | 47 |
| LOC_TYPE | RELATION TO INTERSECTION | Accident | NUM | 47 |
| LOC_WRK_ZNE | LOCATION OF ACC IN WORKZONE | Accident | CHA(2) | 47 |
| LOCN_REL | LOCATION RELIABILITY | Accident | CHA(1) | 47 |
| MILEPOST | MODIFIED REFERENCE POINT | Accident | NUM | 48 |
| NUMVEHS | NUMBER OF VEHICLES INVOLVED | Accident | NUM | 48 |
| OBJECT1 | FIXED OBJECT STRUCK | Accident | NUM | 48 |
| OFF_TYPE | TYPE OF INVESTIGATING OFFICER | Accident | NUM | 48 |
| ON_BRDG | ACCIDENT OCCURRED ON BRIDGE | Accident | CHA(1) | 49 |
| POP_FROM_CITY | POPULATION OF CITY | Accident | NUM | 49 |
| POP_FROM_COUNTY | POPULATION OF COUNTY | Accident | NUM | 49 |
| POP_GRP | URBAN/RURAL POPULATION CODES | Accident | NUM | 49 |
| PUBDMG | PUBLIC PROPERTY DAMAGE | Accident | CHA(1) | 50 |
| RD_CHAR1 | ROAD CHARACTERISTICS | Accident | NUM | 50 |
| RDSURF | ROAD SURFACE CONDITIONS | Accident | NUM | 50 |
| RDWORK | ROAD WORK BEING PERFORMED | Accident | NUM | 50 |
| RODWYCLS | ROADWAY CLASSIFICATION | Accident | CHA(2) | 51 |
| RTE_NBR | ROUTE NUMBER | Accident | CHA(9) | 51 |
| RTE_SYS | ROUTE SYSTEM | Accident | CHA(2) | 51 |
| RTSYSNBR | COMBINED ROUTE SYSTEM/ROUTE NUMBER | Accident | CHA(11) | 52 |
| SCHLBUS | SCHOOL BUS INVOLVED ACCIDENT | Accident | CHA(1) | 52 |
| SEVERITY | ACCIDENT SEVERITY | Accident | CHA(1) | 52 |
| SPEED | POSTED SPEED LIMIT | Accident | CHA(2) | 52 |
| TOT_INJ | NUMBER OF PERSONS INJURED | Accident | NUM | 52 |
| TOT_KILL | NUMBER OF PERSONS KILLED | Accident | NUM | 52 |
| TRF_CNTL | TRAFFIC CONTROL DEVICES | Accident | NUM | 52 |
| TRFCNTLW | TRAFFIC CONTROL WORKING | Accident | NUM | 53 |
| TRVL_DIR | TRAVEL DIRECTION | Accident | CHA(1) | 53 |
| TWNSHIP | TOWNSHIP NUMBER | Accident | NUM | 53 |
| VEH_MOV1 | VEHICLE MOVEMENT | Accident | NUM | 53 |
| WAST_MAT | WASTE MATERIAL CARRIED | Accident | CHA(1) | 54 |
| WEATHER | WEATHER CONDITIONS | Accident | NUM | 55 |
| WEATHER1 | WEATHER CONDITIONS | Accident | NUM | 55 |
| WEATHER2 | WEATHER CONDITIONS | Accident | NUM | 55 |
| WEEKDAY | DAY OF WEEK ACCIDENT OCCURRED | Accident | NUM | 55 |
| WORK_ZONE | WORKZONE MARKED | Accident | CHA(2) | 55 |
| WRKS_PRESNT | WORKER PRESENT | Accident | CHA(1) | 55 |
NOTE: SAS variable names and longer explanatory names are shown above each listing. (See Discussion for in formation on SAS formats.)
DATE ACCIDENT OCCURRED
NON-LABELED VARIABLE
NOTE: YYYYMMDD = Year-Month-Day accident occurred.
DIAGRAM OF ACCIDENT CODE
NOTE: See discussion. This variable does not indicate "what" is struck, only "how" something is struck. In addition, the "head-on" and "sideswipe opposing" codes reflect the direction of the opposing vehicles immediately prior to impact rather than their initial direction.
TYPE OF ACCIDENT
YEAR ACCIDENT OCCURRED
NON-LABELED VARIABLE
NOTE: 'YYYY' = Year of accident. Variable discontinued in 2000.
AMBULANCE NUMBER
NON-LABELED VARIABLE -- Ambulance number
NOTE: Variable added in 1991.
ACCIDENT NUMBER
NON-LABELED VARIABLE
NOTE: 'YYYYDDDNNNN' where YYYY = Year, DDD = Julian day of year, and NNNN = Unique case number (0000-9999).
COUNTY
NON-LABELED VARIABLE
NOTE: 01-87 = County number
ROAD DESIGN
HAZARDOUS MATERIAL CARRIED
NOTE: Variable discontinued in 1990.
HIT AND RUN
NOTE: Variable added in 1990.
HOUR ACCIDENT OCCURRED
NON-LABELED VARIABLE
NOTE: 'HHMM' = Hour and minute that accident occurred ('0000'-'0059'='12 AM - 1259 AM',… '9800'='LEFT BLANK', '9900'='UNKNOWN').
Values before 2003 are rounded to the nearest hour.
INTERCHANGE ELEMENT CODE
NON-LABELED VARIABLE
NOTE: This is a three-character variable giving the code for a certain intersection element where the crash occurred. The coding is either 'ANN' or 'NNN', where "A" is alphabet and "N" is numeric. Three blanks indicate "not in an interchange". Unfortunately, no other detail on the element descriptors is available.
LIGHT CONDITIONS
LOCATION OF PEDESTRIAN/BIKE ACCIDENT
NOTE: Variable discontinued in 1989.
LOCATION OF FIRST HARMFUL EVENT
LOCATION DESCRIPTION
NON-LABELED VARIABLE
NOTE: Variable added in 1990.
RELATION TO INTERSECTION
LOCATION OF ACC IN WORKZONE
NOTE: Variable added in 2003.
LOCATION RELIABILITY
NOTE: Variable added in 1990.
MODIFIED REFERENCE POINT
NON-LABELED VARIABLE
NOTE: This is a reformatted version of the original "Reference Point" variable in the MN files. The reformatting was done to facilitate computer linkage with other files.
NUMBER OF VEHICLES INVOLVED
NON-LABELED VARIABLE
FIXED OBJECT STRUCK
NOTE: (1) Code '00' (No object stuck) and code '21' (Not applicable) are equivalent.
(2) In the 1991 data, the number and percent of "NO OBJECT STRUCK" was significantly lower and the number/percent of "UNKNOWN" significantly higher than in other years. The percent of "UNKNOWN" remains slightly higher (i.e., 4 percent) in later years.
(3) See ACCTYPE (Accident Subfile) and EVENT (Vehicle Subfile).
(4) Variable discontinued in 2000.
TYPE OF INVESTIGATING OFFICER
NOTE: Records coded as OFF_TYPE = "UNKNOWN" have been removed in 1991 and later years to improve quality of data. See Discussion.
ACCIDENT OCCURRED ON BRIDGE
NOTE: Preliminary analyses have shown this variable to be inaccurate. It appears that uncoded cases default to "NO." In addition, note that in bridge analyses based on matching accident and bridge locations, interchange ramp accidents are located to the center of the interchange, which may be a bridge. This will erroneously increase the number of "bridge accidents" unless accounted for.
POPULATION OF CITY
NON-LABELED VARIABLE
NOTE: Variable added in 2003.
POPULATION OF COUNTY
NON-LABELED VARIABLE
NOTE: Variable added in 2003.
URBAN/RURAL POPULATION CODES
PUBLIC PROPERTY DAMAGE
NOTE: Variable added in 1991.
ROAD CHARACTERISTICS
ROAD SURFACE CONDITIONS
ROAD WORK BEING PERFORMED
NOTE: Variable discontinued in 2003.
ROADWAY CLASSIFICATION
NOTE: Created variable added to HSIS accident and roadway inventory files in all states in 1999. See Discussion.
ROUTE NUMBER
NON-LABELED VARIABLE
NOTE: 'NNNNNNNNX' = ROUTE NUMBER (N=0-9, and X is numeric, alpha, or blank. Note that in a few cases with county/township roads, an alpha character will appear in other columns.) This variable is used for file linkage. See RTSYSNBR.
ROUTE SYSTEM
NOTE: See RTSYSNBR.
COMBINED ROUTE SYSTEM/ROUTE NUMBER
NON-LABELED VARIABLE
NOTE: This is a combined version of the RTE_NBR and RTE_SYS variables above. This combining was done to facilitate computer linkage with other files.
SCHOOL BUS INVOLVED ACCIDENT
NOTE: Variable added in 2000. Valid data are not available before 2003.
ACCIDENT SEVERITY
POSTED SPEED LIMIT
NON-LABELED VARIABLE
NOTE: Posted speed limit in miles per hour. '00','99' = 'SPEED LIMIT UNKNOWN'.
NUMBER OF PERSONS INJURED
NON-LABELED VARIABLE
NUMBER OF PERSONS KILLED
NON-LABELED VARIABLE
TRAFFIC CONTROL DEVICES
TRAFFIC CONTROL WORKING
TRAVEL DIRECTION
NOTE: Variable added in 2003.
TOWNSHIP NUMBER
NON-LABELED VARIABLE
NOTE: 000 = Unknown, 001-999 = Township number.
VEHICLE MOVEMENT
NOTE: Variable discontinued in 1990.
WASTE MATERIAL CARRIED
NOTE: Variable discontinued in 1990.
WEATHER CONDITIONS
WEATHER CONDITIONS
WEATHER CONDITIONS
NOTE: The variable WEATHER was replaced by WEATHER1 and WEATHER2 in 2003.
DAY OF WEEK ACCIDENT OCCURRED
WORKZONE MARKED
NOTE: Variable added in 2003.
WORKER PRESENT
NOTE: Variable added in 2003.
| SAS VARIABLE NAME | DESCRIPTION | SAS VARIABLE FILE | FORMAT TYPE | PAGE NO. |
|---|---|---|---|---|
| CASENO | ACCIDENT NUMBER CODE | Vehicle | CHA(11) | 58 |
| CONTRIB1 | FIRST CONTRIBUTING FACTOR | Vehicle | NUM | 58 |
| CONTRIB2 | SECOND CONTRIBUTING FACTOR | Vehicle | NUM | 58 |
| DAMSEV | VEHICLE DAMAGE SEVERITY | Vehicle | CHA(1) | 59 |
| DRV_AGE | AGE OF DRIVER | Vehicle | NUM | 59 |
| DRV_INJ | DRIVER INJURY | Vehicle | CHA(1) | 59 |
| DRV_SEX | SEX OF DRIVER | Vehicle | CHA(1) | 59 |
| EVENT1 | SEQUENCE OF EVENT -1 | Vehicle | CHA(2) | 60 |
| EVENT2 | SEQUENCE OF EVENT -2 | Vehicle | CHA(2) | 60 |
| EVENT3 | SEQUENCE OF EVENT -3 | Vehicle | CHA(2) | 60 |
| EVENT4 | SEQUENCE OF EVENT -4 | Vehicle | CHA(2) | 60 |
| FIRE | FIRE IN VEHICLE | Vehicle | CHA(1) | 61 |
| HAZMTL | VEHICLE CARRYING HAZARDOUS MATERIAL | Vehicle | CHA(1) | 61 |
| INTRANSPORT | WAS VEHICLE IN TRANSPORT | Vehicle | CHA(1) | 61 |
| LICTYPE | VALID DRIVER LICENSE | Vehicle | CHA(1) | 61 |
| MAKE | MAKE OF VEHICLE MATERIAL | Vehicle | CHA(4) | 62 |
| MCAXLDN | MOTOR CARRIER AXLES DOWN | Vehicle | CHA(2) | 62 |
| MCAXLUUP | MOTOR CARRIER AXLES UP | Vehicle | CHA(2) | 62 |
| MCBDYTYP | MOTOR CARRIER BODY TYPE | Vehicle | CHA(2) | 62 |
| MCGVWRCD | MOTOR GROSS VEHICLE WEIGHT CODE | Vehicle | CHA(2) | 62 |
| MCHZPLAC | MOTOR HAZARDOUS MATERIAL PLACARD FLAG | Vehicle | CHA(1) | 63 |
| MCSOURCE | SOURCE OF IDENTIFICATION | Vehicle | CHA(2) | 63 |
| MCTRHTCH | MOTOR TRAILER HITCH CODE | Vehicle | CHA(2) | 63 |
| MISCACT1 | ACTION PRIOR TO ACCIDENT | Vehicle | NUM | 63 |
| MODEL | MOTOR MODEL | Vehicle | CHA(2) | 64 |
| MOST_EVENT | MOST HARMFUL EVENT | Vehicle | CHA(2) | 65 |
| MVCLASS | MOTOR CLASS | Vehicle | CHA(2) | 66 |
| MVTYPE | MOTOR TYPE | Vehicle | CHA(2) | 66 |
| NUMOCCS | NUMBER OF OCCUPANTS | Vehicle | NUM | 66 |
| PHYSCOND | PHYSICAL CONDITION OF DRIVER | Vehicle | NUM | 66 |
| SERIES | SERIES OF VEHICLE | Vehicle | CHA(3) | 66 |
| TOWAWAY | VEHICLE TOWED | Vehicle | CHA(1) | 67 |
| TOWING | TOWING FLAG | Vehicle | CHA(1) | 67 |
| V_DAMAGE | VEHICLE DAMAGE AREA | Vehicle | NUM | 67 |
| VEH_DIR | DIRECTION VEHICLE WAS TRAVELING | Vehicle | NUM | 67 |
| VEH_USE | SPECIAL VEHICLE USE | Vehicle | CHA(2) | 68 |
| VEHNO | RELATIVE VEHICLE NUMBER | Vehicle | NUM | 68 |
| VEHSTATE | STATE OF VEHICLE REGISTRATION | Vehicle | CHA(2) | 68 |
| VEHTYPE | TYPE OF VEHICLE | Vehicle | NUM | 68 |
| VEHYR | MODEL YEAR OF VEHICLE | Vehicle | CHA(4) | 69 |
| WAIVED | COMMERCIAL VEHICLE INSPECTION WAIVED | Vehicle | CHA(1) | 69 |
| WASTE_MT | VEHICLE CARRYING WASTE MATERIAL | Vehicle | CHA(1) | 70 |
NOTE: SAS variable names and longer explanatory names are shown above each listing. (See Discussion for information on SAS formats.)
ACCIDENT NUMBER
NON-LABELED VARIABLE
NOTE: 'YYYYDDDNNNN' where YYYY = Year, DDD = Julian day of year,
NNNN = Unique case number (0000-9999).
FIRST CONTRIBUTING FACTOR
SECOND CONTRIBUTING FACTOR
VEHICLE DAMAGE SEVERITY
AGE OF DRIVER
NON-LABELED VARIABLE
NOTE: 98 = '98 YRS OR OLDER', 99 = 'UNKNOWN'. In the 1990 file, only injured driver information is available. Between 5 - 10 percent of the cases are uncoded after 1990.
DRIVER INJURY
NOTE: (1) This variable was copied from the Occupant Subfile to this Vehicle Subfile beginning in 1990. Prior driver-injury data can be extracted from the Occupant Subfile.
(2) The "NO INJURY" code is new beginning in 1990. However, full data on all uninjured drivers is probably not available until 1991 or 1992. In addition, the "NO INJURY" code is not used after 1991. MN staffs indicate that a blank code also means "NO INJURY", as captured in the format above.
SEX OF DRIVER
NOTE: In 1990, only injured driver information is available. "NS/NOT APPLIC" plus other "ERROR/OTHER CODE" represent approximately 10 percent of the cases for all years.
SEQUENCE OF EVENT ‑1
SEQUENCE OF EVENT ‑2
SEQUENCE OF EVENT ‑3
SEQUENCE OF EVENT ‑4
Collision with
Collision with fixed object
Non-collision
Residual categories
NOTE:Valid data are not available for 2003. No EVENT4 is available for 2004.
FIRE IN VEHICLE
VEHICLE CARRYING HAZARDOUS MATERIAL
WAS VEHICLE IN TRANSPORT
NOTE: Variable added in 2003.
VALID DRIVER LICENSE
NOTE: Variable discontinued in 1990.
MAKE OF VEHICLE
NON-LABELED VARIABLE
NOTE: New variable added in 1990. This is a four character code indicating the vehicle make. While some codes are obvious (e.g., FORD, BUIC, CHEV), others are not as obvious. Approximately 13% of the data are uncoded.
MOTOR CARRIER AXLES DOWN
NON-LABELED VARIABLE
NOTE: Axles down making contact with pavement (00-99).
Variable discontinued in 2003.
MOTOR CARRIER AXLES UP
NON-LABELED VARIABLE
NOTE: Axles up not making contact with pavement (00-99).
Variable discontinued in 2003.
MOTOR CARRIER BODY TYPE
MOTOR GROSS VEHICLE WEIGHT CODE
NOTE: Variable discontinued in 2003.
MOTOR HAZARDOUS MATERIAL PLACARD FLAG
NOTE: Variable discontinued in 2003.
SOURCE OF IDENTIFICATION
NOTE: Variable discontinued in 2003.
MOTOR TRAILER HITCH CODE
NOTE: Variable discontinued in 2003.
ACTION PRIOR TO ACCIDENT
MOTOR MODEL
NON-LABELED VARIABLE
NOTE: Variable discontinued in 2003.
MOST HARMFUL EVENT
NOTE: New variable added in 2003.
MOTOR CLASS
NON-LABELED VARIABLE
NOTE: Variable discontinued in 2003.
MOTOR TYPE
NON-LABELED VARIABLE
NOTE: Variable discontinued in 2003.
NUMBER OF OCCUPANTS
NON-LABELED VARIABLE
NOTE: Number of occupants in the vehicle (0-99).
Variable added in 1991.
PHYSICAL CONDITION OF DRIVER
SERIES OF VEHICLE
NON-LABELED VARIABLE
NOTE: Variable added in 1990. This is a three-character code identifying the vehicle series (e.g., 626, 6LE, CIV) within a given vehicle make. While we do not have a listing of all possible formats, it appears that the data can be "decoded" when combined with MAKE. Approximately 20% of the data are uncoded.
VEHICLE TOWED
TOWING FLAG
NOTE: Variable added in 1991.
VEHICLE DAMAGE AREA
DIRECTION VEHICLE WAS TRAVELING
NOTE: Variable added in 1990.
SPECIAL VEHICLE USE
NOTE: Variable only available for 2003 and 2004.
RELATIVE VEHICLE NUMBER
NON-LABELED VARIABLE
NOTE: Number of vehicle on accident report or relative vehicle number (01-60). Used to link with occupant file.
STATE OF VEHICLE REGISTRATION
NON-LABELED VARIABLE
NOTE: Variable added in 1997. However, all codes are currently blanks.
TYPE OF VEHICLE
MODEL YEAR OF VEHICLE
NON-LABELED VARIABLE
NOTE: Model year of vehicles (NNNN). This variable discontinued in 1991.
COMMERCIAL VEHICLE INSPECTION WAIVED
NOTE: Variable only available for 2003 and 2004.
VEHICLE CARRYING WASTE MATERIAL
NOTE: Variable discontinued in 1990.
| SAS VARIABLE NAME | DESCRIPTION | SAS VARIABLE FILE | FORMAT TYPE | PAGE NO. |
|---|---|---|---|---|
| AGE | AGE OF INJURED/KILLED | Occupant | NUM | 72 |
| AIRBAG | AIRBAG DEPLOYED | Occupant | CHA(2) | 72 |
| ALCOHOL_RESULT | BLOOD ALCOHOL TEST RESULT | Occupant | CHA(2) | 72 |
| ALCOHOL_TEST | BLOOD ALCOHOL TEST PERFORMANCE | Occupant | CHA(1) | 72 |
| BIRTH_DT | BIRTHDAY | Occupant | CHA(8) | 73 |
| CASENO | ACCIDENT NUMBER | Occupant | CHA(11) | 73 |
| CORN_RPT | CORONER REPORT RECORD | Occupant | CHA(1) | 73 |
| DL_CLASS | DRIVER LICENSE CLASS | Occupant | CHA(1) | 73 |
| DL_STATE | DRIVER LICENSE STATE | Occupant | CHA(2) | 73 |
| DL_WITHD | DRIVER LICENSE WITHDRAWAL | Occupant | CHA(1) | 74 |
| DRIV_REC | DRIVER RECOMMENDATION | Occupant | CHA(2) | 74 |
| DRUG_TEST | DRUG TEST PERFORMED | Occupant | CHA(1) | 74 |
| EJECT | EJECTION FROM VEHICLE | Occupant | NUM | 74 |
| EQUIP_TYPE | TYPE OF SAFETY EQUIPMENT | Occupant | CHA(2) | 74 |
| FAT_NUM | FATALITY NUMBER | Occupant | CHA(4) | 75 |
| FATLDATE | FATALITY DATE | Occupant | NUM | 75 |
| HOSP | INJURED TAKEN TO HOSPITAL | Occupant | CHA(1) | 75 |
| HOSPTRAN | TRANSPORTED TO HOSPITAL METHOD | Occupant | CHA(1) | 75 |
| INJ | INJURY SEVERITY | Occupant | CHA(1) | 75 |
| LIS_RSTR | COMPLIANCE WITH LICENSE RESTRICTIONS | Occupant | CHA(1) | 76 |
| PHYSCOND | PHYSICAL CONDITION | Occupant | NUM | 76 |
| RES_CNTY | RESIDENCE COUNTY | Occupant | NUM | 77 |
| REST1 | SAFETY EQUIPMENT USED | Occupant | CHA(1) | 77 |
| SEATPOS | POSITION IN VEHICLE | Occupant | NUM | 78 |
| SEX | SEX OF INJURED/KILLED OCCUPANT | Occupant | CHA(1) | 78 |
| VALID_LICENSE | VALID DRIVER LICENSE | Occupant | CHA(2) | 79 |
| VEHNO | VEHICLE OCCUPIED BY INJURED/ KILLED | Occupant | NUM | 79 |
| VIOLATIONS | DRIVER CITED FOR VIOLATIONS | Occupant | CHA(1) | 79 |
| WORK_REL | WORK RELATED ACCIDENT | Occupant | CHA(1) | 79 |
NOTE: This file only contains data on the injured occupants in the vehicle for 1985-1990 data. Thus, none of the "successes" (non-injured occupants) are included for these years. Beginning in 1991 and 1992, this file contains data on all occupants. See discussion
NOTE: (1) SAS variable names and explanatory names are shown above each listing. (See Discussion for information on SAS formats.)
(2) This file only contains data on the injured occupants in the vehicle for 1985-1990 data. Thus, none of the "successes" (non-injured occupants) are included for these years. Beginning in 1991, this file contains data on all occupants. See discussion.
AGE OF INJURED/KILLED OCCUPANT
NON-LABELED VARIABLE
NOTE: 98 = '98 YRS OR OLDER', 99 = 'UNKNOWN'.
AIRBAG DEPLOYED
NOTE: Variable added in 2000.
BLOOD ALCOHOL TEST RESULT
NOTE: Variable added in 2003.
BLOOD ALCOHOL TEST PERFORMANCE
NOTE: Variable added in 2003.
BIRTHDAY
NON-LABELED VARIABLE
NOTE: Date of birth (YYYYMMDD). Variable added 1991.
ACCIDENT NUMBER
NON-LABELED VARIABLE
NOTE: 'YYYYDDDNNNN' where YYYY = Year, DDD = Julian day of year,
NNNN = Unique case number (0000-9999).
CORONER REPORT RECORD
NOTE: Variable added in 1991.
DRIVER LICENSE CLASS
NOTE: Variable added in 1991.
DRIVER LICENSE STATE
NON-LABELED VARIABLE
NOTE: Two-character State name (i.e., MN). Variable added in 1991.
DRIVER LICENSE WITHDRAWAL
NOTE: Variable added in 1990 and discontinued in 1999.
DRIVER RECOMMENDATION
NOTE: Variable added in 1990.
DRUG TEST PERFORMED
NOTE: Variable added in 2003.
EJECTION FROM VEHICLE
TYPE OF SAFETY EQUIPMENT
NOTE: New variable added in 2000.
FATALITY NUMBER
NON-LABELED VARIABLE
NOTE: Internal fatality number assigned by Minnesota.
Not of use for analysis efforts.
FATALITY DATE
NON-LABELED VARIABLE
NOTE: Date of fatality (YYYYMMDD). Variable added in 1998.
INJURED TAKEN TO HOSPITAL
TRANSPORTED TO HOSPITAL METHOD
NOTE: New variable added in 1991.
INJURY SEVERITY
NOTE: The "NO INJURY" code is new beginning in 1990, since MN did not begin coding uninjured occupants until that year. After 1991, MN staff indicate that a blank code also can mean "NO INJURY" as captured in the format above. However, since additional blank "place holder" occupant records are added to the Occupant File, while not likely the case, there may be some blank codes which represent other injury classes. See Discussion.
COMPLIANCE WITH LICENSE RESTRICTIONS
NOTE: New variable added in 1991.
PHYSICAL CONDITION
NOTE: Codes are not mutually exclusive. If more than one condition exists, officer is most likely to use alcohol-related codes.
RESIDENCE COUNTY
NON-LABELED VARIABLE
NOTE: County of residence (same codes as COUNTY).
Variable added in 1991. Valid data are not available for 1997.
SAFETY EQUIPMENT USED
POSITION IN VEHICLE
SEX OF INJURED/KILLED OCCUPANT
VALID DRIVER LICENSE
NOTE: Variable added in 2003.
VEHICLE OCCUPIED BY INJURED/KILLED
NON-LABELED VARIABLE
NOTE: Vehicle number on accident report. Used to link with vehicle file. Preliminary analyses indicate that pedestrians and bicyclists are often given a VEHNO = '0'.
DRIVER CITED FOR VIOLATIONS
NOTE: Variable added in 2003.
WORK RELATED ACCIDENT
NOTE: Variable added in 1990. Data appear to be consistent in 1991 and later. Variable discontinued in 2003.
| SAS VARIABLE NAME | DESCRIPTION | SAS VARIABLE FILE | FORMAT TYPE | PAGE NO. |
|---|---|---|---|---|
| AADT | CALCULATED AVERAGE AADT | Roadlog | NUM | 83 |
| ACCESS | CONTROL OF ACCESS | Roadlog | NUM | 83 |
| ADLN_RD1 | ADDITIONAL LANES - ROAD 1 | Roadlog | CHA(1) | 83 |
| ADLN_RD2 | ADDITIONAL LANES - ROAD 2 | Roadlog | CHA(1) | 83 |
| BAS_TKR1 | BASE THICKNESS - ROAD 1 | Roadlog | CHA(3) | 84 |
| BEGMP | CALCULATED BEGIN MILEPOST | Roadlog | NUM | 84 |
| BRK_CD | BREAK CODE | Roadlog | NUM | 84 |
| COMM_ADT | CALCULATED AVERAGE COMMERCIAL AADT | Roadlog | NUM | 84 |
| COUNTY | COUNTY | Roadlog | NUM | 85 |
| CURB1 | CURBS - ROAD 1 | Roadlog | CHA(1) | 85 |
| CURB2 | CURBS - ROAD 2 | Roadlog | CHA(1) | 85 |
| DIR_CDE | DIRECTION CODE | Roadlog | CHA(2) | 85 |
| ENDMP | CALCULATED ENDING MILEPOST | Roadlog | NUM | 85 |
| FED_AID | FEDERAL AID SYSTEM | Roadlog | CHA(1) | 85 |
| FED_SYSD | FEDERAL AID SYSTEM - DESIGNATED | Roadlog | CHA(1) | 86 |
| FED_SYSR | FEDERAL AID SYSTEM - REGULAR | Roadlog | CHA(1) | 86 |
| FUNC_CLS | FUNCTIONAL CLASS | Roadlog | NUM | 86 |
| H_COUNT | NUMBER OF COUNT STATIONS PER SECTION | Roadlog | NUM | 86 |
| INTE_CAT | INTERSECTION CATEGORY | Roadlog | NUM | 87 |
| INV_DTE | INVENTORY DATE | Roadlog | CHA(8) | 87 |
| LANEWID | LANE WIDTH | Roadlog | NUM | 87 |
| LSHL_TY2 | LEFT SHOULDER TYPE - ROAD 2 | Roadlog | CHA(2) | 88 |
| LSHL_TYP | LEFT SHOULDER TYPE - ROAD 1 | Roadlog | CHA(2) | 88 |
| LSHL_WD2 | LEFT SHOULDER WIDTH - ROAD 2 | Roadlog | CHA(2) | 89 |
| LSHLDWID | LEFT SHOULDER WIDTH - ROAD 1 | Roadlog | CHA(2) | 89 |
| MED_TYPE | MEDIAN TYPE | Roadlog | CHA(1) | 89 |
| MEDWID | MEDIAN WIDTH (IN FEET) | Roadlog | CHA(2) | 90 |
| MVMT | MILLION VEHICLE MILES TRAVELED | Roadlog | NUM | 90 |
| NBRVOL | TOTAL NUMBER OF TRAFFIC VOLUME COUNTS | Roadlog | NUM | 90 |
| NBRVOLB | NUMBER OF BLANK TRAFFIC VOLUME COUNTS | Roadlog | NUM | 90 |
| NBRVOLF | NUMBER OF FULL TRAFFIC VOLUME COUNTS | Roadlog | NUM | 90 |
| NO_LANE1 | NUMBER THROUGH LANES TOWARDS INCREASING MILEPOINTS | Roadlog | CHA(1) | 90 |
| NO_LANE2 | NUMBER THROUGH LANES TOWARDS DECREASING MILEPOINTS | Roadlog | CHA(1) | 90 |
| NO_LANES | TOTAL NUMBER OF LANES | Roadlog | NUM | 91 |
| ONEWAY | DIVIDED AND ONE-WAY CODE | Roadlog | CHA(1) | 91 |
| PARKING1 | PARKING ON ROAD 1 | Roadlog | CHA(1) | 91 |
| PARKING2 | PARKING ON ROAD 2 | Roadlog | CHA(1) | 91 |
| REF_PST | REFERENCE POST | Roadlog | CHA(3) | 92 |
| REMARK | REMARKS - TYPE OF RECORD | Roadlog | CHA(2) | 92 |
| RODWYCLS | ROADWAY CLASSIFICATION | Roadlog | CHA(2) | 92 |
| ROW | RIGHT OF WAY WIDTH | Roadlog | CHA(3) | 92 |
| RSHL_TY2 | RIGHT SHOULDER TYPE - ROAD 2 | Roadlog | CHA(2) | 93 |
| RSHL_TYP | RIGHT SHOULDER TYPE - ROAD 1 | Roadlog | CHA(2) | 93 |
| RSHL_WD2 | RIGHT SHOULDER WIDTH - ROAD 2 | Roadlog | CHA(2) | 94 |
| RSHLDWID | RIGHT SHOULDER WIDTH - ROAD 1 | Roadlog | CHA(2) | 94 |
| RTE_NBR | ROUTE NUMBER | Roadlog | CHA(9) | 94 |
| RTE_SYS | ROUTE SYSTEM | Roadlog | CHA(2) | 95 |
| RTSYSNBR | COMBINED ROUTE SYSTEM/ROUTE NUMBER | Roadlog | CHA(11) | 95 |
| SEG_LNG | CALCULATED SECTION LENGTH | Roadlog | NUM | 95 |
| SIDE_WLK | SIDEWALKS | Roadlog | CHA(1) | 95 |
| STM_SEW | STORM SEWERS | Roadlog | CHA(1) | 96 |
| SUF_TYP1 | SURFACE SPECIFICATION NUMBER - ROAD 1 | Roadlog | CHA(4) | 96 |
| SUF_TYP2 | SURFACE SPECIFICATION NUMBER - ROAD 2 | Roadlog | CHA(4) | 96 |
| SUR_TKR1 | SURFACE THICKNESS – ROAD 1 | Roadlog | CHA(3) | 96 |
| SUR_TKR2 | SURFACE THICKNESS – ROAD 2 | Roadlog | CHA(3) | 96 |
| SURF_TY2 | SURFACE TYPE - ROAD 2 | Roadlog | CHA(2) | 96 |
| SURF_TYP | SURFACE TYPE - ROAD 1 | Roadlog | CHA(2) | 96 |
| SURF_WD2 | SURFACE WIDTH - ROAD 2 (IN FEET) | Roadlog | CHA(2) | 97 |
| SURF_WID | SURFACE WIDTH - ROAD 1 (IN FEET) | Roadlog | CHA(2) | 97 |
| TURN_LN | TURNING LANES TOWARD INCREASING MILEPOSTS | Roadlog | CHA(1) | 97 |
| TURN_LN2 | TURNING LANES TOWARD DECREASING MILEPOSTS | Roadlog | CHA(1) | 97 |
| UPDATE_ | DATE OF UPDATE | Roadlog | NUM | 98 |
| URB_MNC | URBAN/MUNICIPAL CODE | Roadlog | NUM | 98 |
| VOLGRP | TRAFFIC VOLUME GROUP | Roadlog | CHA(2) | 98 |
| VOLTYP | TRAFFIC VOLUME TYPE | Roadlog | CHA(1) | 98 |
| YEAR | YEAR OF TRAFFIC | Roadlog | CHA(4) | 98 |
NOTE: Prior to 1994, approximately one-third of the records on this file are "false records" coded other than 'blank'. These must be taken into account when using this file -- see introductory discussion.
NOTE: SAS variable names and explanatory names are shown above each listing. (See Discussion for information on SAS formats.)
CALCULATED AVERAGE AADT
NOTE: This is the calculate average AADT (annual average daily traffic) assigned to this section. It is averaged over years (1985-87 in the 1987 File, 1988-89 in the 1989 File), and over counters within the section. If no counters exist, the average is brought forward from the preceding upstream section. See Discussion. Approximately 2%-4% of the sections have AADT which is either uncoded or '0.' While the percentages of uncoded/"0" seem to vary across years, we can see no discernable pattern.
CONTROL OF ACCESS
ADDITIONAL LANES ‑ ROAD 1
ADDITIONAL LANES ‑ ROAD 2
NOTE: Road 2 data only exist for divided roadways. In addition, since there is no accurate way of linking a given accident with the proper road, and the low number of "disagreements" between Road 1 and Road 2 data, it is suggested that accidents always be linked with Road 1 data for ease of handling. (See earlier discussion.)
BASE THICKNESS ‑ ROAD 1
NOTE: This is the thickness of the pavement base to the nearest tenth of an inch (e.g., 094 = 9.4 inches). Over 99% of the data are coded as "Not Applicable", which probably means that a blank also means "Not Coded".
CALCULATED BEGIN MILEPOST
NON-LABELED VARIABLE
NOTE: Calculated beginning milepost. See Discussion.
BREAK CODE
CALCULATED AVERAGE COMMERCIAL AADT
COUNTY
NON-LABELED VARIABLE
NOTE: 01-87 = COUNTY NUMBER.
CURBS - ROAD 1
CURBS - ROAD 2
NOTE: Road 2 data only exist for divided roadways. In addition, since there is no accurate way of linking a given accident with the proper road, and because of the low number of "disagreements" between Road 1 and Road 2 data, it is suggested that accidents always be linked with Road 1 data for ease of handling. (See discussion.)
DIRECTION CODE
NOTE: Variable added in 2001.
CALCULATED ENDING MILEPOST
NON-LABELED VARIABLE
NOTE: Calculated ending milepost. See Discussion.
FEDERAL AID SYSTEM
FEDERAL AID SYSTEM ‑ DESIGNATED
FEDERAL AID SYSTEM ‑ REGULAR
FUNCTIONAL CLASS
Rural
Urban
NOTE: Beginning with 1990 data, codes 13 and 15 are no longer valid. Code 13 was changed to 12 and 15 was changed to 14. This explains why there are 'zeros' in the Guidebook tables' cells for these codes.
NUMBER OF COUNT STATIONS PER SECTION
NON-LABELED VARIABLE
NOTE: Number of traffic count stations per section.
INTERSECTION CATEGORY
NOTE: This is a "point" variable describing the intersection at the beginning of the segment.
INVENTORY DATE
NON-LABELED VARIABLE
NOTE: YYYYMMDD = DATE OF MOST RECENT INVENTORY, 00000000 = DATE OF INVENTORY UNKNOWN.
LANE WIDTH
NON-LABELED VARIABLE
NOTE: This variable shows the calculated lane width. Lane width (in feet) is not provided in the raw data file from Minnesota. Instead, this variable is calculated using the following method suggested by Minnesota staff:
(1) If roadway is undivided (i.e., ONEWAY not equal to 'D'), and if a curb is not present (CURB1 = 'N'), then: LANEWID = SURF_WID/NO_LANES. If a curb is present (CURB1 = 'L', 'R', or 'B'), then LANEWID = 12;
(2) If roadway is divided (i.e., ONEWAY = 'D') and if a curb is not present (CURB1 = 'N'), then: LANEWID = (SURF_WID + SURF_WD2)/NO_LANES. If a curb is present (CURB1 = 'L', 'R', or 'B'), then LANEWID = 12.
LEFT SHOULDER TYPE ‑ ROAD 2
LEFT SHOULDER TYPE ‑ ROAD 1
NOTE: (1) Composite shoulders (i.e., part paved, part unpaved) are coded as "Mn" or "Nn" in the above format. The "n" or numeric part of these codes defines the width of the paved part of the shoulder. The shoulder width variables (e.g., LSHLDWID, RSHLWID) will provide the total shoulder width in these composite cases.
(2) Road 2 data only exist for divided roadways. In addition, since there is no accurate way of linking a given accident with the proper road, and because of the low number of "disagreements" between Road 1 and Road 2 data, it is suggested that accidents always be linked with Road 1 data for ease of handling. (See earlier discussion.)
LEFT SHOULDER WIDTH - ROAD 2
LEFT SHOULDER WIDTH - ROAD 1
NON-LABELED VARIABLE
NOTE: This is the actual left shoulder width in feet. A blank means "not applicable"; a "UN" means "unknown"; and a "00" means "no shoulder".
(1) Road 2 data only exist for divided roadways. In addition, since there is no accurate way of linking a given accident with the proper road, and because of the low number of "disagreements" between Road 1 and Road 2 data, it is suggested that accidents always be linked with Road 1 data for ease of handling. (See earlier discussion.)
(2) When MN/DOT codes shoulder width, it is total shoulder width. For sod/gravel, it is from edge of lane to ditch, guardrail, or taper to ditch. When there is partial paved and partial sod/gravel, the shoulder type should be coded as "composite."
In the composite codes under shoulder type, the shoulder type codes gives the feet of paved shoulder within the measurement. The total measure for shoulder width presented here is the width of the total composite shoulder -- from edge of lane to ditch. When the shoulder is "paved", the width is total width of the paved shoulder. There may be some cases where the coding is slightly in error. For example, a paved width may have some added sod/gravel which is unmeasured. However, if there is a wide area of sod/gravel, the shoulder type will be "composite" and the total width will be measured. There are also some cases where composite shoulders may be coded in error; however, it can be assumed that the total width is for all types of shoulders.
MEDIAN TYPE
MEDIAN WIDTH (IN FEET)
MILLION VEHICLE MILES TRAVELED
NON-LABELED VARIABLE
NOTE: The Million Vehicle Miles Traveled on road segment. Created variable added in 1999 for all HSIS roadway-inventory files. See Discussion.
TOTAL NUMBER OF TRAFFIC VOLUME COUNTS
NON-LABELED VARIABLE
NOTE: The number of total (full plus blank) volume fields in the record containing AADT values. Variable discontinued in 1999.
NUMBER OF BLANK TRAFFIC VOLUME COUNTS
NON-LABELED VARIABLE
NOTE: The number of blank (unused) volume fields in the record.
Variable discontinued in 1999.
NUMBER OF FULL TRAFFIC VOLUME COUNTS
NON-LABELED VARIABLE
NOTE: Number of volume fields in the record containing AADT values. Variable discontinued in 1999.
NUMBER THROUGH LANES TOWARDS INCREASING MILEPOINTS
NUMBER THROUGH LANES TOWARDS DECREASING MILEPOINTS
NOTE: This variable and NO_LANE1 must be summed to obtain the total number of lanes on a section of roadway, even for 2-lane, 2-way roadways. This has been done under NO_LANES.
TOTAL NUMBER OF LANES
NOTE: This is the sum of NO_LANE1 + NO_LANE2, and is the total number of lanes on a section of roadway.
DIVIDED AND ONE‑WAY CODE
PARKING ON ROAD 1
PARKING ON ROAD 2
NOTE: Road 2 data only exist for divided roadways. In addition, since there is no accurate way of linking a given accident with the proper road, and because of the low number of "disagreements" between Road 1 and Road 2 data, it is suggested that accidents always be linked with Road 1 data for ease of handling. (See earlier discussion.)
REFERENCE POST
NON-LABELED VARIABLE
NOTE: Reference post number ('000'-'999'). New variable added in 1996.
REMARKS ‑ TYPE OF RECORD
NOTE: Prior to 1994, approximately one-third of the records on this file are "false records" coded other than 'blank'. These must be taken into account when using this file -- see introductory discussion. These false records are deleted from the files for 1994 and later years.
ROADWAY CLASSIFICATION
NOTE: Created variable added to HSIS accident and roadway inventory files in all states in 1999. See Discussion.
RIGHT OF WAY WIDTH
NON-LABELED VARIABLE
NOTE: Average right of way width in feet. New variable added in 1994.
RIGHT SHOULDER TYPE - ROAD 2
RIGHT SHOULDER TYPE - ROAD 1
NOTE: (1) Composite shoulders (i.e., part paved, part unpaved) are coded as "Mn" or "Nn" in the above format. The "n" or numeric part of these codes defines the width of the paved part of the shoulder. The shoulder width variables (e.g., LSHLDWID, RSHLWID) will provide the total shoulder width in these composite cases.
(2) Road 2 data only exist for divided roadways. In addition, since there is no accurate way of linking a given accident with the proper road, and because of the low number of "disagreements" between Road 1 and Road 2 data, it is suggested that accidents always be linked with Road 1 data for ease of handling. (See earlier discussion.)
RIGHT SHOULDER WIDTH - ROAD 2
RIGHT SHOULDER WIDTH - ROAD 1
NON-LABELED VARIABLE
NOTE: This is the actual right shoulder width in feet. A blank means "not applicable"; a "UN" means "unknown"; and a "00" means "no shoulder".
(1) Road 2 data only exist for divided roadways. In addition, since there is no accurate way of linking a given accident with the proper road, and because of the low number of "disagreements" between Road 1 and Road 2 data, it is suggested that accidents always be linked with Road 1 data for ease of handling. (See earlier discussion.)
(2) When Mn/DOT codes shoulder width, it is total shoulder width. For sod/gravel, it is from edge of lane to ditch, quardrail, or taper to ditch. When there is partial paved and partial sod/gravel, the shoulder type should be coded as "composite."
In the composite codes under shoulder type, the shoulder type codes gives the feet of paved shoulder within the measurement.
The total measure for shoulder width presented here is the width of the total composite shoulder -- from edge of lane to ditch.
When the shoulder is "paved", the width is total width of the paved shoulder. There may be some cases where the coding is slightly in error. For example, a paved width may have some added sod/gravel which is unmeasured. However, if there is a wide area of sod/gravel, the shoulder type will be "composite" and the total width will be measured. There are also some cases where composite shoulders may be coded in error; however, it can be assumed that the total width is for all types of shoulders.
ROUTE NUMBER
NON-LABELED VARIABLE
NOTE: 'NNNNNNNNX' = ROUTE NUMBER (N=0-9, and X is numeric, alpha, or blank. Note that in a few cases with county/township roads, an alpha character will appear in other columns.) This variable is used for file linkage * see RTSYSNBR.
ROUTE SYSTEM
NOTE: See RTESYSNBR.
COMBINED ROUTE SYSTEM/ROUTE NUMBER
NON-LABELED VARIABLE
NOTE: This is a combined version of the RTE_NBR and RTE_SYS variables above. This combining was done to facilitate computer linkage with other files.
CALCULATED SECTION LENGTH
NON-LABELED VARIABLE
NOTE: For 1990 and later files, the calculated section length is based on true beginning and ending mileposts where available from the Reference Post File. Prior to 1990, it was based on the difference between the standard beginning and ending mileposts. See discussion.
SIDEWALKS
STORM SEWERS
NOTE: High percentage of "UNKNOWN" codes.
SURFACE SPECIFICATION NUMBER ‑ ROAD 1
SURFACE SPECIFICATION NUMBER ‑ ROAD 2
NOTE: Road 2 data only exist for divided roadways. In addition, since there is no accurate way of linking a given accident with the proper road, and because of the low number of "disagreements" between Road 1 and Road 2 data, it is suggested that accidents always be linked with Road 1 data for ease of handling. (See earlier discussion.)
SURFACE THICKNESS – ROAD 1
SURFACE THICKNESS – ROAD 2
NOTE: The variable SUR_TKR1 was discontinued in 1996. The variable SUR_TRK2 was only recorded for the year 1997.
SURFACE TYPE - ROAD 2
SURFACE TYPE - ROAD 1
NOTE: Road 2 data only exist for divided roadways. In addition, since there is no accurate way of linking a given accident with the proper road, and because of the low number of "disagreements" between Road 1 and Road 2 data, it is suggested that accidents always be linked with Road 1 data for ease of handling. (See earlier discussion.)
SURFACE WIDTH - ROAD 1 (IN FEET)
SURFACE WIDTH - ROAD 2 (IN FEET)
NOTE: Road 2 data only exist for divided roadways. In addition, since there is no accurate way of linking a given accident with the proper road, and because of the low number of "disagreements" between Road 1 and Road 2 data, it is suggested that accidents always be linked with Road 1 data for ease of handling. (See earlier discussion.)
TURNING LANES TOWARD INCREASING MILEPOSTS
TURNING LANES TOWARD DECREASING MILEPOSTS
DATE OF UPDATE
NON-LABELED VARIABLE
NOTE: Most recent date on which record was modified (YYYYMMDD). Variable added in 1994.
URBAN/MUNICIPAL CODE
TRAFFIC VOLUME GROUP
NOTE: Variable added in 1989.
TRAFFIC VOLUME TYPE
YEAR OF TRAFFIC
NON-LABELED VARIABLE
NOTE: Denotes year of volume count.
NOTE: The Intersection File consists of variable length records ranging from 228-1204 bytes each, depending on the number of intersecting routes and legs. Each record consists of a fixed-length "general" portion with variables describing the entire intersection (e.g.,"General Environment", "Traffic Control Device"), and a variable length portion which describes up to six segments (routes), and up to two legs (approaches) for each segment. Variables for segments include such variables as "Route Number" and "Number of Legs", and variables for each leg include multiple years of AADT information and "Number of Approach Thru Lanes." This variable-length record has been converted into a SAS-formatted, fixed length record for ease of use. In this conversion, each variable for every possible leg on each route had to be given a separate SAS variable name. The listing below includes the SAS names for all "general" variables and example names for the route-specific and leg-specific variables. Unlike the other file descriptions, for clarity, the variables are primarily listed in raw-file order rather than alphabetical order.
| SAS VARIABLE NAME | DESCRIPTION | SAS VARIABLE FILE | FORMAT TYPE | PAGE NO. |
|---|---|---|---|---|
| RTE_SYS | ROUTE SYSTEM | Intersct-chg | CHA(2) | 102 |
| RTE_NBR | ROUTE NUMBER | Intersct-chg | CHA(9) | 102 |
| INT_SYNB | COMBINED RTE_SYS/RTE_NBR | Intersct-chg | CHA(11) | 102 |
| MILEPOST | MODIFIED REFERENCE POINT LOCATION | Intersct-chg | NUM | 102 |
| REF_PNT | REFERENCE POINT | Intersct-chg | CHA(10) | 103 |
| ELEM_NBR | INTERCHANGE ELEMENT CODE | Intersct-chg | CHA(3) | 103 |
| ENDMP | CALCULATED ENDING MILEPOST | Intersct-chg | NUM | 103 |
| INT_TYPE | INTERSECTION TYPE | Intersct-chg | NUM | 103 |
| DESC_ | INTERSECTION DESCRIPTION | Intersct-chg | NUM | 104 |
| TYPEDESC | INTERSECTION DESCRIPTION-REVISED | Intersct-chg | NUM | 104 |
| RAIL_NBR | RAILROAD CROSSING NUMBER | Intersct-chg | CHA(8) | 104 |
| TRAF_DEV | TRAFFIC CONTROL DEVICES | Intersct-chg | NUM | 105 |
| TRF_CNTL | TRAFFIC CONTROL DEVICES-REVISED | Intersct-chg | NUM | 105 |
| SIGN_PRO | TRAFFIC SIGNALS PROGRESSION | Intersct-chg | NUM | 105 |
| SIGN_TIM | TRAFFIC SIGNALS TIMING | Intersct-chg | NUM | 105 |
| SIGN_CON | TRAFFIC SIGNALS CONSTRUCTION | Intersct-chg | NUM | 106 |
| SIGN_PLA | SIGNAL HEAD PLACEMENT | Intersct-chg | NUM | 106 |
| SIGN_PED | TRAFFIC SIGNALS PEDESTRIAN SIGNALS | Intersct-chg | NUM | 106 |
| TRAF_TMO | FLASHING SIGNAL TIME ON | Intersct-chg | CHA(2) | 106 |
| TRAF_TMF | FLASHING SIGNAL TIME OFF | Intersct-chg | CHA(2) | 106 |
| TRAF_PHS | TRAFFIC SIGNALS NUMBER OF PHASES | Intersct-chg | NUM | 106 |
| TRAF_PRE | TRAFFIC SIGNALS PREEMPTION | Intersct-chg | NUM | 106 |
| RDWY_LGH | ROADWAY LIGHTING | Intersct-chg | NUM | 107 |
| GEN_ENIV | GENERAL ENVIRONMENT | Intersct-chg | NUM | 107 |
| SPEC_ENV | SPECIFIC ENVIRONMENT | Intersct-chg | NUM | 107 |
| DIST_CAT | CATEGORY ASSIGNED BY DISTRICT | Intersct-chg | CHA(2) | 107 |
| CNTL_CAT | CENTRAL OFFICE CATEGORY | Intersct-chg | CHA(2) | 107 |
| SFTY_IMY | SAFETY IMPROVEMENT YEAR | Intersct-chg | CHA(2) | 107 |
| SFTY_IMD | SAFETY IMPROVEMENT DISTRICT | Intersct-chg | CHA(1) | 108 |
| SFTY_PRJ | SAFETY IMPROVEMENT PROJECT NUMBER | Intersct-chg | CHA(2) | 108 |
| SFTY_CLS | SAFETY IMPROVEMENT CLASSIFICATION | Intersct-chg | CHA(2) | 108 |
| EFEC_DTE | DATE OF ACCIDENT GEOCODING | Intersct-chg | NUM | 108 |
| NBR_RTES | NUMBER OF ROUTES INTO INTERSECTION | Intersct-chg | NUM | 108 |
| NBR_LEGS | NUMBER OF LEGS INTO INTERSECTION | Intersct-chg | NUM | 108 |
| TRAFCNTL | TRAFFIC CONTROL DEVICES | Intersct-chg | NUM | 108 |
| SAS VARIABLE NAME | DESCRIPTION | SAS VARIABLE FILE | FORMAT TYPE | PAGE NO. |
|---|---|---|---|---|
| RTESYS1 | ROUTE SYSTEM - ROUTE 1 | Intersct-chg | CHA(2) | 111 |
| RTENBR1 | ROUTE NUMBER - ROUTE 1 | Intersct-chg | CHA(9) | 111 |
| REFPNT1 | REFERENCE POINT-ROUTE 1 | Intersct-chg | CHA(10) | 111 |
| RDESC1 | ROAD DESCRIPTION | Intersct-chg | NUM | 112 |
| LOLIMT1 | SEGMENT 1 LOWER LIMIT | Intersct-chg | NUM | 112 |
| UPLIMT1 | SEGMENT 1 UPPER LIMIT | Intersct-chg | NUM | 113 |
| NBR_LEG1 | NUMBER OF LEGS ON SEGMENT 1 | Intersct-chg | NUM | 113 |
NOTE: Variables for Segments 2-6 would be identical, with last character denoting the Segment number (e.g., RTESYS2, RTESYS3, etc.)
| SAS VARIABLE NAME | DESCRIPTION | SAS VARIABLE FILE | FORMAT TYPE | PAGE NO. |
|---|---|---|---|---|
| LEGNBR11 | SEGMENT 1, LEG NUMBER 1 | Intersct-chg | NUM | 115 |
| DIRECT11 | SEGMENT 1, LEG 1 DIRECTION | Intersct-chg | NUM | 115 |
| AADT111 | SEGMENT 1, LEG 1, YEAR 1 AADT | Intersct-chg | NUM | 115 |
| ADTYR111 | SEGMENT 1, LEG 1, YEAR 1 | Intersct-chg | CHA(2) | 115 |
| AADT112 | SEGMENT 1, LEG 1, YEAR 2 AADT | Intersct-chg | NUM | 116 |
| ADTYR112 | SEGMENT 1, LEG 1, YEAR 2 | Intersct-chg | CHA(2) | 116 |
| AADT113 | SEGMENT 1, LEG 1, YEAR 3 AADT | Intersct-chg | NUM | 116 |
| ADTYR113 | SEGMENT 1, LEG 1, YEAR 3 | Intersct-chg | CHA(2) | 116 |
| AADT114 | SEGMENT 1, LEG 1, YEAR 4 AADT | Intersct-chg | NUM | 116 |
| ADTYR114 | SEGMENT 1, LEG 1, YEAR 4 | Intersct-chg | NUM | 116 |
| AADT115 | SEGMENT 1, LEG 1, YEAR 5 AADT | Intersct-chg | NUM | 116 |
| ADTYR115 | SEGMENT 1, LEG 1, YEAR 5 | Intersct-chg | CHA(2) | 116 |
| AP_SPD11 | SEGMENT 1, LEG 1, APPROACH SPEED LIMIT | Intersct-chg | NUM | 117 |
| APCNTL11 | SEGMENT 1, LEG 1, APPROACH TRAFFIC CONTROL | Intersct-chg | NUM | 117 |
NOTE: Variables for all other Legs would be identical. The first numerical character at the end of each variable denotes the segment number, the second numerical character denotes the leg number, and the third numerical character (if present) denotes the year of the data. For example, DIRECT21 would denote the direction variable for segment 2, leg 1. In like fashion, AADT223 would denote the AADT for segment 2, leg 2, year 3.
| SAS VARIABLE NAME | DESCRIPTION | SAS VARIABLE FILE | FORMAT TYPE | PAGE NO. |
|---|---|---|---|---|
| RTE_SYS | ROUTE SYSTEM | Intersct-chg | CHA(2) | 102 |
| RTE_NBR | ROUTE NUMBER | Intersct-chg | CHA(9) | 102 |
| INT_SYNB | COMBINED RTE_SYS/RTE_NBR | Intersct-chg | CHA(11) | 102 |
| MILEPOST | MODIFIED REFERENCE POINT LOCATION | Intersct-chg | NUM | 102 |
| REF_PNT | REFERENCE POINT | Intersct-chg | CHA(10) | 103 |
| ELEM_NBR | INTERCHANGE ELEMENT CODE | Intersct-chg | CHA(3) | 103 |
| ENDMP | CALCULATED ENDING MILEPOST | Intersct-chg | NUM | 103 |
| INT_TYPE | INTERSECTION TYPE | Intersct-chg | NUM | 103 |
| DESC_ | INTERSECTION DESCRIPTION | Intersct-chg | NUM | 104 |
| TYPEDESC | INTERSECTION DESCRIPTION-REVISED | Intersct-chg | NUM | 104 |
| RAIL_NBR | RAILROAD CROSSING NUMBER | Intersct-chg | CHA(8) | 104 |
| TRAF_DEV | TRAFFIC CONTROL DEVICES | Intersct-chg | NUM | 105 |
| TRF_CNTL | TRAFFIC CONTROL DEVICES-REVISED | Intersct-chg | NUM | 105 |
| SIGN_PRO | TRAFFIC SIGNALS PROGRESSION | Intersct-chg | NUM | 105 |
| SIGN_TIM | TRAFFIC SIGNALS TIMING | Intersct-chg | NUM | 105 |
| SIGN_CON | TRAFFIC SIGNALS CONSTRUCTION | Intersct-chg | NUM | 106 |
| SIGN_PLA | SIGNAL HEAD PLACEMENT | Intersct-chg | NUM | 106 |
| SIGN_PED | TRAFFIC SIGNALS PEDESTRIAN SIGNALS | Intersct-chg | NUM | 106 |
| TRAF_TMO | FLASHING SIGNAL TIME ON | Intersct-chg | CHA(2) | 106 |
| TRAF_TMF | FLASHING SIGNAL TIME OFF | Intersct-chg | CHA(2) | 106 |
| TRAF_PHS | TRAFFIC SIGNALS NUMBER OF PHASES | Intersct-chg | NUM | 106 |
| TRAF_PRE | TRAFFIC SIGNALS PREEMPTION | Intersct-chg | NUM | 106 |
| RDWY_LGH | ROADWAY LIGHTING | Intersct-chg | NUM | 107 |
| GEN_ENIV | GENERAL ENVIRONMENT | Intersct-chg | NUM | 107 |
| SPEC_ENV | SPECIFIC ENVIRONMENT | Intersct-chg | NUM | 107 |
| DIST_CAT | CATEGORY ASSIGNED BY DISTRICT | Intersct-chg | CHA(2) | 107 |
| CNTL_CAT | CENTRAL OFFICE CATEGORY | Intersct-chg | CHA(2) | 107 |
| SFTY_IMY | SAFETY IMPROVEMENT YEAR | Intersct-chg | CHA(2) | 107 |
| SFTY_IMD | SAFETY IMPROVEMENT DISTRICT | Intersct-chg | CHA(1) | 108 |
| SFTY_PRJ | SAFETY IMPROVEMENT PROJECT NUMBER | Intersct-chg | CHA(2) | 108 |
| SFTY_CLS | SAFETY IMPROVEMENT CLASSIFICATION | Intersct-chg | CHA(2) | 108 |
| EFEC_DTE | DATE OF ACCIDENT GEOCODING | Intersct-chg | NUM | 108 |
| NBR_RTES | NUMBER OF ROUTES INTO INTERSECTION | Intersct-chg | NUM | 108 |
| NBR_LEGS | NUMBER OF LEGS INTO INTERSECTION | Intersct-chg | NUM | 108 |
| TRAFCNTL | TRAFFIC CONTROL DEVICES | Intersct-chg | NUM | 108 |
NOTE: SAS variable names and explanatory names are shown above each listing. (See Discussion for information on SAS formats.)
ROUTE SYSTEM
ROUTE NUMBER
NON-LABELED VARIABLE
NOTE: 'NNNNNNNNX' = ROUTE NUMBER (N=0-9, and X is numeric, alpha, or blank. Note that in a few cases with county/township roads, an alpha character will appear in other columns.) This variable is used for file linkage * see INT_SYNB.
COMBINED RTE_SYS/RTE_NBR
NON-LABELED VARIABLE
NOTE: This is a combined version of the RTE_NBR and RTE_SYS variables above. This combining was done to facilitate computer linkage with other files.
MODIFIED REFERENCE POINT LOCATION
NON-LABELED VARIABLE
NOTE: (1) This is a reformatted version of the original "Reference Point" variable in the MN files. The reformatting was done to facilitate computer linkage with other files.
(2) Variable discontinued in 2001.
REFERENCE POINT
NON-LABELED VARIABLE
NOTE: Reference point location - Reformatted to MILEPOST for linkage.
INTERCHANGE ELEMENT CODE
NON-LABELED VARIABLE
NOTE: The reader should first see the Note under INT_TYPE below. ELEM_NBR is a three-character variable giving the code for interchange elements (e.g., mainline between ramps, exit ramp, intersection at ramp terminal on crossing roadway, etc.) These codes are only present for a subset of interchanges in the file - primarily diamond interchanges - and denote that this record is a supplemental record for this interchange. They are retained in the file to assist in linking accidents to specific interchange elements within these diamond interchanges -- the same code is found in the Accident File. The coding is either "ANN" or "NNN", where "A" is alpha and "N" is numeric. The formats for the possible codes (i.e., possible interchange element types) is very complex. It is not presented here, but can be obtained from HSIS staff.
CALCULATED ENDING MILEPOST
NON-LABELED VARIABLE
NOTE: The calculated ending milepost. See Discussion. Variable added in 2001.
INTERSECTION TYPE
NOTE: (1) As detailed in the earlier Discussion, basic intersections (i.e., those not part of an interchange) are coded as "3". Each interchange will have a record in the file coded as INT_TYPE = "1". In addition, some interchanges (primarily diamond interchanges) will have supplemental records in the file which will have the same milepost as the type "1" record (and the same general descriptors), but which will be coded as type "2" -- intersections within an interchange. These type "2" supplemental records will also have an Interchange Element Code as a further identifier. See ELEM_NBR above.
(2) AADT data for “Type 2 = Intersection within interchange” are not updated on a regular basis. Contact HSIS staff for more information.
INTERSECTION DESCRIPTION
NON-LABELED VARIABLE
NOTE: (1) Due to its complexity in the Minnesota raw files, this variable was reformatted into TYPEDESC (see below).
(2) Variable discontinued in 2001.
INTERSECTION DESCRIPTION-REVISED
NOTE: In some cases, intersection types denoted by codes 20-34 will not match exactly with information on number of legs in the NBR_LEGS variable. The Minnesota Department of Transportation has been notified of this problem and it should be corrected in data in future years.
RAILROAD CROSSING NUMBER
NON-LABELED VARIABLE
NOTES: (1) ' ' = 'NOT STATED', 'NNNNNNNA' = Railroad crossing number.
(2) No data available since 1997.
TRAFFIC CONTROL DEVICES
NON-LABELED VARIABLE
NOTE: Due to its complexity in the Minnesota raw files, this variable was reformatted into TRF_CNTL (see below).
TRAFFIC CONTROL DEVICES-REVISED
NOTE: Variable discontinued in 2001.
TRAFFIC SIGNALS PROGRESSION
TRAFFIC SIGNALS TIMING
TRAFFIC SIGNALS CONSTRUCTION
SIGNAL HEAD PLACEMENT
TRAFFIC SIGNALS PEDESTRIAN SIGNALS
FLASHING SIGNAL TIME ON
FLASHING SIGNAL TIME OFF
TRAFFIC SIGNALS NUMBER OF PHASES
TRAFFIC SIGNALS PREEMPTION
ROADWAY LIGHTING
GENERAL ENVIRONMENT
SPECIFIC ENVIRONMENT
CATEGORY ASSIGNED BY DISTRICT
NON-LABELED VARIABLE
NOTE: Intersection/interchange category assigned by individual districts only limited use, and no format available.
CENTRAL OFFICE CATEGORY
NON-LABELED VARIABLE
NOTE: ' ' = No category assigned by central office.
'01' - '99' = Category assigned by central office.
SAFETY IMPROVEMENT YEAR
NON-LABELED VARIABLE
NOTE: Safety improvement year where ' ' = No safety improvement,
'70' - 'XX' = Year of improvement.
SAFETY IMPROVEMENT DISTRICT
NON-LABELED VARIABLE
NOTE: ' ' = 'No safety improvement', '1' - '9' = District responsible for improvement.
SAFETY IMPROVEMENT PROJECT NUMBER
NON-LABELED VARIABLE
NOTE: ' ' = ' No safety improvement ', '01' - '99' = Project number assigned.
SAFETY IMPROVEMENT CLASSIFICATION
NON-LABELED VARIABLE
NOTE: ' ' = ' No safety improvement ', '01' - '99' = Safety improvement code.
DATE OF ACCIDENT GEOCODING
NON-LABELED VARIABLE
NOTE: 0=Accident data coded since system startup, YYMMDD=Date from which accident data are geocoded to intersection.
NUMBER OF ROUTES INTO INTERSECTION
NON-LABELED VARIABLE
NOTE: 1-9 = Number of routes involved.
NUMBER OF LEGS INTO INTERSECTION
NON-LABELED VARIABLE
NOTE: 1-9 = Number of legs in intersection.
TRAFFIC CONTROL DEVICES
NOTE: Variable added in 2001.
| SAS VARIABLE NAME | DESCRIPTION | SAS VARIABLE FILE | FORMAT TYPE | PAGE NO. |
|---|---|---|---|---|
| RTESYS1 | ROUTE SYSTEM - ROUTE 1 | Intersct-chg | CHA(2) | 111 |
| RTENBR1 | ROUTE NUMBER - ROUTE 1 | Intersct-chg | CHA(9) | 111 |
| REFPNT1 | REFERENCE POINT-ROUTE 1 | Intersct-chg | CHA(10) | 111 |
| RDESC1 | ROAD DESCRIPTION | Intersct-chg | NUM | 112 |
| LOLIMT1 | SEGMENT 1 LOWER LIMIT | Intersct-chg | NUM | 112 |
| UPLIMT1 | SEGMENT 1 UPPER LIMIT | Intersection | NUM | 113 |
| NBR_LEG1 | NUMBER OF LEGS ON SEGMENT 1 | Intersct-chg | NUM | 113 |
NOTE: Variables for Segments 2-6 would be identical, with last character denoting the Segment number (e.g., RTESYS2, RTESYS3, etc.)
NOTE: SAS variable names and explanatory names are shown above each listing. (See Discussion for information on SAS formats.)
ROUTE SYSTEM - ROUTE 1
NOTE: This variable is used in linkage to other files. See Note under REFPNT1 below.
ROUTE NUMBER - ROUTE 1
NON-LABELED VARIABLE
NOTE: 'NNNNNNNNX' = ROUTE NUMBER (N=0-9, and X is numeric, alpha, or blank. Note that in a few cases with county/township roads, an alpha character will appear in other columns.) This variable is used for file linkage. See REFPNT1.
REFERENCE POINT-ROUTE 1
NON-LABELED VARIABLE
NOTE: Reference point location on Route number 1. In over 97% of the cases, Route 1 is usually the "primary" route used for general intersection location. Thus, RTESYS1 and RTENBR1 is usually the same as RTE_SYS and RTE_NBR, and REFPNT1 is the same as REF_PNT. For the crossing roads, RTESYS2, RTENBR2 and REFPNT2 will be used for the first crossing route, RTESYS3, etc. for the second crossing route, etc. While the original REF_PNT was converted to MILEPOST for ease of computer linkage, REFPNT1-X has not been converted. However, HSIS staff has developed a computer program to allow linkage of these crossing routes with other files. The user can request the program or variables from the linked files from our staff.
ROAD DESCRIPTION
NOTE: Coding for this variable is somewhat questionable since two identical intersections may be coded into different categories. Specifically, it appears that the number of lanes shown at the first of each category (e.g., "3/5," or "4/6") could be interpreted by the district coders as either the total number of lanes (counting left-turn lanes) or the total number of through lanes. The main problem appears to be in categories "2" and "4."
Here, for example, an undivided four-lane roadway with opposing left-turn lanes at the intersection might be coded as a category "2" or a category "4." It also appears that category "6" is a rather broad category. Here, all divided roadway with a median continuing up to the intersection proper which have four or more through lanes and either single or double left-turn lanes would be coded as a "6."
SEGMENT 1 LOWER LIMIT
NON-LABELED VARIABLE
NOTE: Lower reference point limit: 0000-9999 = Dist. in ft from intersection towards beginning of route used as lower search limit for accident occurrences.
SEGMENT 1 UPPER LIMIT
NON-LABELED VARIABLE
NOTE: Upper reference point limit: 0000-9999 = Dist. in ft from intersection towards end of route used as upper search limit for accident occurrences.
NUMBER OF LEGS ON SEGMENT 1
NON-LABELED VARIABLE
NOTE: Number of legs described in this record: 1-2 = Number of legs.
| SAS VARIABLE NAME | DESCRIPTION | SAS VARIABLE FILE | FORMAT TYPE | PAGE NO. |
|---|---|---|---|---|
| LEGNBR11 | SEGMENT 1, LEG NUMBER 1 | Intersct-chg | NUM | 115 |
| DIRECT11 | SEGMENT 1, LEG 1 DIRECTION | Intersct-chg | NUM | 115 |
| AADT111 | SEGMENT 1, LEG 1, YEAR 1 AADT | Intersct-chg | NUM | 115 |
| ADTYR111 | SEGMENT 1, LEG 1, YEAR 1 | Intersct-chg | CHA(2) | 115 |
| AADT112 | SEGMENT 1, LEG 1, YEAR 2 AADT | Intersct-chg | NUM | 116 |
| ADTYR112 | SEGMENT 1, LEG 1, YEAR 2 | Intersct-chg | CHA(2) | 116 |
| AADT113 | SEGMENT 1, LEG 1, YEAR 3 AADT | Intersct-chg | NUM | 116 |
| ADTYR113 | SEGMENT 1, LEG 1, YEAR 3 | Intersct-chg | CHA(2) | 116 |
| AADT114 | SEGMENT 1, LEG 1, YEAR 4 AADT | Intersct-chg | NUM | 116 |
| ADTYR114 | SEGMENT 1, LEG 1, YEAR 4 | Intersct-chg | NUM | 116 |
| AADT115 | SEGMENT 1, LEG 1, YEAR 5 AADT | Intersct-chg | NUM | 116 |
| ADTYR115 | SEGMENT 1, LEG 1, YEAR 5 | Intersct-chg | CHA(2) | 116 |
| AP_SPD11 | SEGMENT 1, LEG 1, APPROACH SPEED LIMIT | Intersct-chg | NUM | 117 |
| APCNTL11 | SEGMENT 1, LEG 1, APPROACH TRAFFIC CONTROL | Intersct-chg | NUM | 117 |
NOTE: Variables for all other Legs would be identical. The first numerical character at the end of each variable denotes the segment number, the second numerical character denotes the leg number, and the third numerical character (if present) denotes the year of the data. For example, DIRECT21 would denote the direction variable for segment 2, leg 1. In like fashion, AADT223 would denote the AADT for segment 2, leg 2, year 3.
NOTE: SAS variable names and explanatory names are shown above each listing. (See Discussion for information on SAS formats.)
SEGMENT 1, LEG NUMBER 1
NON-LABELED VARIABLE
NOTE: Leg number of first leg: 0 = 'NOT APPLICABLE', 1-12 = Number assigned.
SEGMENT 1, LEG 1 DIRECTION
SEGMENT 1, LEG 1, YEAR 1 AADT
NON-LABELED VARIABLE
NOTE: 000000 = Not applicable or no traffic, 000001-999999 = 2-way volume on leg, most recent available year.
Most AADT's are probably not current. The user can determine which year the AADT was collected for each leg from the "AADT Year" variable attached to each leg. However, we have found that the "AADT Year" will seldom be the current (file) year, and that the year of the AADT count can be different for different legs of the same intersection. Unfortunately, we cannot suggest a method for "updating" the AADT data to later years. Since multiple years data are often shown in the file, the user may be able to develop a "trend-related update", but we cannot assure that the estimates will be correct.
SEGMENT 1, LEG 1, YEAR 1
NON-LABELED VARIABLE
NOTE: Year AADT111 was collected: 'YY' or YY = Last two digits of year, ' ',' 0','00', 0, or blank = No AADT available.
This variable can either be a numeric or a character variable.
SEGMENT 1, LEG 1, YEAR 2 AADT
NON-LABELED VARIABLE
NOTE: See AADT111 above.
SEGMENT 1, LEG 1, YEAR 2
NON-LABELED VARIABLE
NOTE: See AADT111 above.
SEGMENT 1, LEG 1, YEAR 3 AADT
NON-LABELED VARIABLE –- See AADT111 above.
NON-LABELED VARIABLE
NOTE: See AADT111 above.
SEGMENT 1, LEG 1, YEAR 3
NON-LABELED VARIABLE
NOTE: See AADT111 above.
SEGMENT 1, LEG 1, YEAR 4 AADT
NON-LABELED VARIABLE
NOTE: See AADT111 above.
SEGMENT 1, LEG 1, YEAR 4
NON-LABELED VARIABLE
NOTE: See AADT111 above.
SEGMENT 1, LEG 1, YEAR 5 AADT
NON-LABELED VARIABLE
NOTE: See AADT111 above.
SEGMENT 1, LEG 1, YEAR 5
NON-LABELED VARIABLE
NOTE: See AADT111 above.
SEGMENT 1, LEG 1, APPROACH SPEED LIMIT
NON-LABELED VARIABLE
NOTE: 00 = 'UNKNOWN', 01-70 = Approach speed in MPH.
SEGMENT 1, LEG 1, APPROACH TRAFFIC CONTROL
If INT_TYPE (intersection type) is anything except a
Railroad grade crossing (i.e., INT_TYPE ne 5):
If INT_TYPE is railroad grade crossing (i.e., INT_TYPE = 5):
