Foursquare ITP assisted in the evaluation of the effectiveness of transit signal priority (TSP) on several corridors in Washington, DC. We contributed to the development of the bus measures for the project and then led the evaluation of bus measures for the project including runtimes, runtime reliability, and schedule deviation. We also analyzed intersection spacing, runtime reliability, and bus person throughput to prioritize the expansion of TSP to additional intersections, and the removal of TSP at ineffective intersections. This analysis included processing of WMATA’s detailed Trace Model in R, extensive calculations for the various measures in each effort, and the production of graphics to visualize results.