Cognitive mapping of transfer: A new approach to understand transfer behaviour
Transfer is a fundamental component of transit journey that expands the spatial coverage of transit service to satisfy increasingly diversifying travel needs. Despite the benefits that transfers can offer, transferring a transit service or mode is generally perceived as a burden to the whole transit journey experience. The conventional approach of reflecting the inconvenience of transfer has been through integrating the additional time and cost incurred during transfer, or transfer penalty that encapsulates subjective and physiological factors in the mode choice model in the form of generalised transfer costs. This study builds upon the hypothesis that transit users will have a preference for the direction of travel towards their transfer point. A total of 11,409 single transfer bus journeys were derived from Brisbane's go card dataset. Each journey's origin, transfer, and destination points were projected to a standardised two dimensional Euclidean space by applying translation, rotation and compression/dilation transformation. As next, the grid based hierarchical clustering was used to divide the Euclidean space into 150 cells to quantify the "preference" for transfer direction and position based on the number of transfer points in each cell. Majority of bus journeys conducted have made a transfer either near the origin or destination. Less number of transit journeys are realised if one is required to make a transfer that is deviated far from the straight line connecting the origin and destination. The straight line between origin and destination could be considered as the private vehicle path perceived by travellers. The deviation from the straight line may imply the impedance of transfer, which is likely to reduce the attractiveness of transit option. Findings from this study present a new approach to explain the transfer and associated travel behaviours.