A decision support system for the choice of medium-capacity transit system
Tsai, Yu Luen
Date of Issue2010
School of Civil and Environmental Engineering
The rapid growth in many urban areas has resulted in traffic congestion, social inequity, and environmental problems. To control these problems, many cities have turned to urban transit systems to serve travel demand. The mass rapid rail transit (MRT) system has been implemented in many metropolitan areas. However, many cities do not have either the financial resources to afford a MRT system or the passenger demand to justify it. To improve public transport services, what is needed for such cities is an appropriate transit system which has higher capacity than a regular bus (RB) system and cheaper than the MRT. There are several medium-capacity transit systems that can meet this requirement. Such systems include Bus Rapid Transit (BRT), Light Rapid Transit (LRT), Guided Bus, Automated Guideway Transit (AGT) and Automated Light Rapid Transit (ALRT). Clearly, in the selection of an appropriate medium-capacity transit system for a study area, the option of retaining the existing transit system (usually RB) should also be considered as an alternative. In the past, studies that dealt with the evaluation of alternative transit systems have been largely based on either a single factor (often cost), or on a few factors but with the alternatives compared on each factor individually. To select a suitable public transit system, one has to simultaneously consider and compare several system attributes some of which are quantitative while others are qualitative. In this research, the evaluation shall include both performance and sustainability attributes. After examining a set of preliminary performance and sustainability factors, three attributes are selected for testing the technical feasibility of each transit system alternatives and twelve attributes are used for comparing these alternative systems. A methodology is developed in this study to integrate these decision factors (i.e., system attributes) in the selection of an appropriate medium-capacity transit system for a given area in a rational and organized manner.