Evaluating the potential mobility benefits of transit signal priority with connected vehicle technology

Public transit helps alleviate traffic congestion, however, it is often not the most preferred mode of transportation because of its unreliability and excessive delays. Transit Signal Priority (TSP) prioritizes the movement of transit vehicles through a signalized intersection to avoid delays and improve travel time reliability. The performance of TSP could potentially be enhanced through connected vehicle (CV) technology. The objective of this study was to evaluate the potential mobility benefits of TSP with CV technology (TSPCV). The specific objectives were to analyse the effect of TSPCV on (a) buses in the street with TSPCV (b) all other vehicles that are not buses in the street with TSPCV and (c) all vehicles on the cross-streets. Three microscopic simulation models: the Base model, the TSP model, and the TSPCV model were developed based on a 3.5-mile corridor with transit operations in West Palm Beach, Florida. The Base model was calibrated and validated to represent field conditions. The mobility benefits were quantified based on travel time, average vehicle delay, and cross-street delay. Results showed that buses and all other vehicles in the TSPCV model experienced up to 20.54% and 14.61% reduction in travel times, respectively. TSPCV operations results caused up to 33.64% and 23.66% reduction in the average vehicle delay time for buses and all other vehicles, respectively. Although the TSPCV provided significant reductions in average delay on the main street, no significant reduction on the cross-street delays was observed. The performance of the TSPCV was also consistently better than TSP. The study results showed the potential of TSPCV deployment in enhancing traffic mobility in corridors with transit operations.