Assessing The Effects Of Deploying Bus Exclusive Lanes On Urban Roads On Vehicle Emissions

Nowadays, devoting extended efforts to develop public transportation systems has become an effective way to resolve the traffic congestion and environmental pollution problems. In this background, deploying bus exclusive lanes on urban roads is an important part in developing public transportation systems with priority in China. It has been found that the installation of bus exclusive lanes in some cities worldwide has substantially improved the quality of traffic operations and service levels. However, most of the existing research on bus exclusive lanes has concentrated on analyzing traffic operational improvements and the design of bus stops for before and after installations. There has been a lack of studies on the analysis of the effects of setting bus exclusive lanes on vehicle emissions.This thesis conducts studies on issues associated with the development and designs of bus excusive lanes, traffic simulation models and vehicle emission models, as well as their inter-relationships. It is intended to develop a quantitative method for evaluating the impact of installating different types of bus exclusive lanes on vehicle emissions in order to be able analyze the implementation outcome of bus exclusive lanes from both traffic and environment perspectives. To this end, the thesis first analyzes the driving and exhaust emission characteristics by using PEMS. Further, it establishes vehicle emission models for buses by introducing the concept of Vehicle Specific Power (VSP). Then, it builds a traffic simulation platform using VISSIM for the Western 3rd Ring Express Roads with different design schemes of bus exclusive lanes including central bus lanes, curbe bus lanes and no bus lanes. Additionally, it analyzes and compares the total emissions as well as emission pollution intensities at different time periods and around interchanges for different design schemes of bus exclusive lanes. It is found from the analysis that different design schemes of bus exclusive lanes are closely related to vehicle emissions. The vehicle emissions are reduced significantly after the installation of bus exclusive lanes. However, vehicle emissions are increased during the peak hours at congested interchanges. The analysis results from this thesis provide a new approach and evaluation tool for analyzing the environmental impact in installing bus exclusive lanes on urban roads.