Analysis of Naturalistic Driving Study Data: Offset Left-Turn Lanes

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February 21st, 2015

Report S2-S08B-RW-1

The purpose of this research project was to demonstrate one application of the SHRP 2 Naturalistic Driving Study (NDS) data, showing how these data can be used to answer a highway safety question and provide guidance for the implementation of safety countermeasures. The specific safety countermeasure evaluated in this project is offset left-turn lanes. The research team evaluated the effect of left-turn lane offset on gap-acceptance behavior, which serves as a surrogate safety measure for this study. Specifically, the objective was to evaluate left-turning gap rejection and acceptance by a large number of drivers at a large number of intersections with a broad distribution of left-turn lane offsets (ranging from negative to positive).

Credit: SHRP 2, Transportation Research Board of the National Academies