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Early research suggested protected left-turn signalization had clear safety benefits over permissive left-turn signalization. Yet, subsequent research on when and where to use protected left-turn signalization focused more on vehicle delay and throughput than on safety. Based on such studies, it would...

This study evaluated the approach-level safety performance of left-turn phases at signalized intersections, including permissive, protected-permissive (PPLT), protected indications, and flashing yellow arrow (FYA). Data collection included exact dates of traffic signal changes, high-resolution datasets...

This study compares the performance of left-turn phasing to provide quantifiable benefits of one phasing over another. From the analysis, guidelines are developed for determining the type of left-turn phasing based on left-turn volume, opposing through volume and lane geometry.