Technical Summary
FHWA
Mar-08
This document is a technical summary of the Federal Highway Administration report, "Safety Evaluation of Center Two-Way Left-Turn Lanes on Two-Lane Roads." The objective of this study was to evaluate the safety effectiveness of installing Two-Way Left-Turn Lanes (TWLTLs) on rural roads as measured by crash frequency before and after the installation of the TWLTLs. The study also examined the effects of this strategy on specific crash types; total, injury, and rear-end crashes were examined in a rigorous analysis, while a cursory analysis was performed for head-on, intersection, and nonintersection crashes. The results of the analysis indicate statistically significant reductions at the 95% confidence level in total, injury, and rear-end crashes for the combined results of the four states examined. Further results are discussed in this TechBrief.
Safety Evaluation of Center Two-Way Left-Turn Lanes on Two-Lane Roads
highway safety
two way left turn lanes
two lane highways
highway design
accidents
rear end collisions
head on collisions
countermeasures
before and after studies
evaluation and assessment
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