Study of Truck Driver Behavior at Onset of Yellow Traffic Signal Indication for the Design of Yellow Times

Abstract

Traffic signal violations by drivers are a leading contributor to crashes at signalized intersections. The yellow indication is used to inform drivers of an upcoming change in the status of the traffic signal. Yellow-interval durations are currently calculated to provide dilemma zone protection for passenger cars. Due to differences in vehicle characteristics and driver characteristics, heavy trucks such as tractor-trailers behave differently at the onset of a yellow-indication. The research presented in this thesis characterizes the difference in driver behavior between truck and light-duty vehicle driver behavior at the onset of yellow-indication and then revises the yellow timing procedures to address the truck requirements.

A dataset of 910 stop-go records was collected using a truck driving simulator located at the Virginia Tech Transportation Institute (VTTI). Participant drivers were placed in a simulated urban environment with a speed limit of 45 MPH and instructed to drive as they would regularly drive in such a situation. Participant drivers were recruited using the VTTI participant database.

Using the data collected as part of this research effort, statistical models were created to model driver perception-reaction times (PRTs) and deceleration levels considering driver attributes (age) and the time to the intersection at the onset of yellow. The data collected, along with the statistical models developed were compared to data collected and statistical models created by the same research organization in 2008 in a similar study of passenger car driver behavior. Lastly, a Monte-Carlo simulation was conducted to develop appropriate yellow indication timings to provide adequate dilemma zone protection for trucks.