California Partners for Advanced Transportation Technology

This report investigates impacts to local traffic operations at intersections adjacent to signal preemption by SPRINTER commuter trains and countermeasures that would minimize these impacts. Optimization models have been developed to estimate the waiting queue at the end of the preemption operation and to quickly clear the queue while minimizing overall traffic delay. Based on the optimization models, optimized signal timing plans for a total of 10 intersections were proposed, which are designed to facilitate the clearance of the queue accumulated during the preemption, as well as to assure that no major queue backup develops on the travel direction parallel to the train tracks. The analysis and simulation indicate that the intersection delay can be reduced as much as 24 percent as a result of implementing the optimal timing. This study also recommends further consideration of countermeasures involving advanced train detections.