Analysis of Flows and Speeds of Urban Transit Systems for Consideration of Modal Transition in a Corridor

TLDR: Some preliminary results on the optimal mix of regular and express bus services in a given corridor are discussed, including the travel demand estimates and transit system parameters under which a transition from the regular bus mode to an optimal mix is mandated.

Abstract: As a transit corridor 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 significant characteristics that must be considered in the transition are the capacity and average speed of each mode, since they impact passenger waiting times and invehicle travel times, respectively, as well as operating costs. Data on stated, as well as observed, maximum flows and average speeds of routes have been collected from many sources and analysed. In addition to intrinsic variations, there is considerable scatter in the data caused, in part, by the lack of information about the differences in the transit systems for which data are available, e.g. the number of transit routes passing through a corridor. Various modes considered suitable for the south Calgary corridor are ranked in terms of 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. Some preliminary results on the optimal mix of regular and express bus services in a given corridor are discussed, including the travel demand estimates and transit system parameters under which a transition from the regular bus mode to an optimal mix is mandated.