Spatial variation of transit service quality preferences in Dar-es-Salaam

Abstract

Commuter preferences for transit service quality are of great importance to transit service providers and regulatory agencies. The point of view of potential passengers is fundamental for evaluating transit service quality as they are envisaged to be the real consumers of the planned services and can therefore be considered the most suitable judges. A stated preference survey of daily commuters to the central business district (CBD) in the city of Dar-es-Salaam, Tanzania, was carried out to elicit preferences towards the proposed Dar Rapid Transit (DART) service. Preferences towards the proposed DART service are considered to vary based on the residential location of the potential users. These preferences are evaluated on the attributes travel time, fare and comfort. A binary logit model was applied to establish utility functions that were analysed spatially in a GIS, where a utility value was computed for each spatial unit. This paper accordingly analyses spatial variation of transit service quality preferences for the proposed DART service using geo-spatial techniques. The study uses a scenario-based approach to evaluate the effect of the proposed DART service by comparing the ‘without DART’ scenario, a case representing the existing public transport (daladala), and a ‘DART’ scenario, representing the future proposed DART system. The results indicate that the proposed DART attributes considered in the study have a significant effect on DART service quality. The results further reveal that utility values are significantly varying spatially, particularly dependent upon distance to CBD. Comfort is the most important attribute in zones up to 5km from the CBD, travel fare is more important in zones between 5 and 15km from the CBD, while travel time is more important in zones beyond 15km distance from the CBD. The overall results indicate that the DART is likely to be more attractive than the existing public transport system.