Comparative Analysis Between Regular Diesel Bus And BRT Vehicle On Emission Character Based On VSP Parameter

In recent years, more departments have given priority to the development of the public transport system to reduce the imbalance between the development of urban traffic and the environment protection or energy conservation. Bus rapid transit system (i.e. BRT), a kind of sustainable option for public transport system, has been in widespread use. However, most of the existing studies on bus rapid transit have concentrated on analyzing the design of infrastructure and operation mode. There was rare research related to quantitative analysis of BRT's influence on a decrease of emission in public transport system.After vehicle specific power (VSP) parameter which adapt to heavy-duty diesel bus in China's specific driving environment is introduced, an emission prediction method of heavy-duty diesel bus is established, which aim to compare the emission character between regular diesel bus and BRT vehicle in the perspective of time and space and further provide the theoretical support for Beijing's public traffic management policy implementation. To this end, the operating data and emission data of heavy-duty diesel buses in Beijing in real road conditions were collected with portable emission measurement system (PEMS) and global positioning system (GPS). Furthermore, the parameters used for heavy-duty diesel buses' VSP were chosen in this thesis and the VSP equation has been introduced to an emission prediction method for heavy-duty diesel bus. Then, the proposed method was used to predict the emission character of regular diesel bus and BRT vehicle within the 5rd Ring Roads of Beijing. Their emission character were analyzed and compared in the perspective of time (peak hours and off-peak hours) and space (none-bus lane, bus lanes and the bus stations). The results showed that BRT system play an obvious role to reduce emission compared with regular diesel bus, especially durning peak hours near the bus station. This thesis provides a practical evaluation method for transit bus environmental influence.