Improved driver responses at intersections with red signal countdown timers

•Driver behavior was observed for 67 Oregon drivers in a simulated environment.•The LME model predicted first headways at signals with RSCT with 95% accuracy.•Signals with RSCT are predicted to reduce first vehicle headways by 0.72 s.•Presence of a RSCT improves intersection efficiency by reducing start-up lost time.

Traffic Signal Countdown Timers (TSCTs) are innovative, practical and cost effective technologies with the potential to improve efficiency at signalized intersections. The purpose of these devices is to assist motorists in decision-making at signalized intersections with real-time signal duration information. This study focused specifically on driver responses in the presence of a Red Signal Countdown Timer (RSCT). A Linear Mixed Effect (LME) model was developed to predict the effect of RSCT on the headway of the first vehicle waiting on a red signal. The model predicted 0.72 s reduction in the headway of the first queued vehicle resulting from the presence of RSCT, while the observed difference in mean headway was 0.82 s. This result is suggestive of a reduction in start-up lost time at signalized intersections, i.e., an improvement in signalized intersection efficiency when an RSCT is present.

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