Traffic Controller Performance during Time-of-Day Transition at Coordinated Actuated Signal Systems

Modern traffic signal controllers supply various transition methods that attempt to mitigate disruptions to normal signal operations during changes in time-of-day (TOD) timing plans. Comprehensive performance evaluations of transition operations during changes in TOD timing plans using three real traffic controllers are presented: the McCain 170E, the Econolite 2070 ATC, and the ASC/3-2100. Evaluation results based on hardware-in-the-loop simulation at a test site with four coordinated-actuated signalized intersections in Virginia indicated that (a) transition operation performance varied because of differences in the transition methods of the different controllers, (b) the Minimax family of transition methods (i.e., Shortway in the 170E controller and Smooth in the 2070 ATC controller) generally outperformed others, (c) the faster start of the transition operation available in the ASC/3-2100 controller provided significant benefits over the 2070 ATC controller, and (d) the 170E controller outperformed both the 2070 ATC and the ASC/3-2100 controllers.