Date, time & venue 
2011-11-07;7:00-8:00 p.m;Wang Gungwu Theatre, The University of Hong Kong

Jointly organized with Institute of Transport Studies, HKU; supported by HKIE Civil Division

Programme Highlights

As a transit route evolves with time (over several decades) due to land use and other changes, the public transit mode (or mix of modes) that serves it may have to transition from one to another several times. Some results on the mix of regular and limited-stop bus services in a given route are discussed, including the transit system parameters under which a transition from regular bus to a mix is optimal. For details, see http://www.hku.hk/hkuits/DTLS2011.htm.

Speaker

Professor Chan Wirasinghe won a US Fulbright Scholarship to study transportation engineering at the University of California at Berkeley and completed his MS in 1973 and Ph.D. in 1976. He is currently a Professor in the Department of Civil Engineering, and was Dean of Engineering from 1994-2006. Dr. Wirasinghe's research interests are in urban public transportation, airports, transport in developing countries and mitigation of natural disasters. He has over 200 publications & keynote presentations, and is the Co-Editor-in-Chief of the Journal of Advanced Transportation. He is a Fellow of the Canadian Academy of Engineering.

Lecture Abstract

As a transit route evolves with time (over several decades) due to land use and other changes, the public transit mode (or mix of modes) that serves it may have to transition from one to another several times. Two of the characteristics that must be considered in the transition are the capacity and average speed of each mode. They impact the passenger waiting times and in-vehicle travel times respectively, as well as operating costs. Data on observed maximum flows and average speeds of routes have been collected from sources worldwide and analyzed. In addition to intrinsic variations, there is scatter in the data caused in part by lack of information about some aspects. For example, information on transit priority at traffic signals that influences average speed is not available in all cases. A discussion of where passenger "waiting time" is spent, and its relationship to the (i) type of service, and (ii) trip purpose, and (iii) availability of real time bus arrival information is given. Various modes considered suitable for the South Calgary corridor are ranked in terms of the line capacity and average speed. The thresholds are those at which a mode transition is essential. However, mode transitions may occur well in advance of such thresholds if a new modal mix is optimal for the corridor in terms of minimizing the sum of the costs to the users and the operator. An early transition is from a regular (all-stop) bus route to a route served by both regular and limited-stop buses, sometimes called bus rapid transit (BRT). Some results on the mix of regular and limited-stop bus services in a given route are discussed, including the transit system parameters under which a transition from regular bus to a mix is optimal. It is argued that passenger-Km's is the right measure of travel demand that should be considered. A simple expression and methodology applicable to any bus route is presented.