ASSESSMENT OF TRANSFER PENALTY TO BUS RIDERS IN TAIPEI: A DISAGGREGATE DEMAND MODELING APPROACH

A transfer penalty to bus riders has long been recognized as an important factor characterizing the service performance of a transit system. Nevertheless, the way the transfer penalty is treaated in current transit network design and improvement planning processes is rather subjective. The transfer penalty is usually treated by use of either subjective values assigned by transit planners or time-value proxies inferred from activities irrelevant to transfers in transit travel. In this paper, the transfer penalty is assessed in terms of monetary and time units with a disaggregate demand modeling approach. The models developed take a binary logit format with two alternative path choices, one that requires a transfer en route and another that does not. Data collected from 1,850 randomly sampled transit users in Taipei are used for model calibration. The penalty of one bus-to-bus transfer is approximately equivalent to the cost of 4.5 N.T. dollars (14 U.S. cents), 30 min of in-bus travel, or 10 min of waiting at a bus stop. The assessment results suggest that in current practice transit planners may underestimate the transfer penalty to bus riders. Some characteristics of transit travel in Taipei are also explored and discussed.