Reduce Bus Bunching with a Real-Time Speed Control Algorithm Considering Heterogeneous Roadway Conditions and Intersection Delays

This paper investigates bus bunching issues encountered with a single bus line. A real-time speed control model was proposed with the objective of minimizing variations in bus headway. Three cases of a typical road infrastructure for bus lines were studied. Two main factors that influence the stability of bus service–namely, signalized intersection delays and heterogeneous roadway conditions—were studied in the modeling process. In addition, other common variables were considered, including the time required for passengers to board a bus and alight from it. Compared with findings from prior literature, that frequently assumed homogeneous roadway infrastructure conditions and ignored intersection delays. The built model output the degree of speed adjustment required in accordance with different roadway configurations and the congestion level at each road section. A case study was designed to test the performance of the proposed model, based on the data collected from 40 bus stops, on Bus route No. 600 in Xi'an, China. Results showed that the proposed model could effectively restrain the problems posed by headway deviations and reduce travel time for the passengers.