Development of City-Specific Driving Cycles for Transit Buses Based on VSP Distributions: Case of Beijing

Abstract

With the rapid increase of automobile ownership, the city of Beijing, China, faces challenging issues with regard to traffic congestion and vehicle emissions. In seeking solutions to these issues, developing and improving public transportation systems is considered one of the most feasible and promising strategies because these systems have high passenger-carrying capacity and low pollution on a per passenger basis. Driving cycles reflect traffic conditions, and thus vehicle emissions, and form a scientific base to further improve bus operations. This paper is intended to develop city-specific driving cycles for transit buses for Beijing. The operational data of 126 buses were collected by using a portable global positioning system (GPS) for three types of bus routes: the bus rapid transit (BRT) line, express line, and regular line. Through analysis of the operating characteristics, a methodology for developing driving cycles is proposed based on the parameter of vehicle-specific power (VSP) distribution. Then, by applying this methodology, driving cycles for BRT, express, and regular lines are developed accordingly. Finally, the developed driving cycles are evaluated. Based on the analysis, the proposed driving cycles are able to reflect the real-world operating characteristics of transit buses better than other driving cycles. Furthermore, the emission factors generated based on the developed driving cycles are lower on average than those predicted by using the default driving cycles in the motor vehicle emission simulator (MOVES).