Use of smart card data for zonal level public transit OD matrix estimation: literature review and research gaps

In public transport smart cards are primarily used for fare collection purpose. During last two decades a tremendous amount of research has been done to use this big data for planning to real time operation and control. One of the applications of smart card data is the estimation of public transit origin destination matrix (tOD). Primary focus of this article is to summarize the current literature on tOD estimation which includes processes of data cleansing, estimation of unknowns, validation of developed algorithms, and ultimately zone to zone transit OD (ztOD) estimation. Estimation of unknowns includes boarding and alighting estimation of passengers, and transfer detection (consisting of maximum transfer distance and time). However, the review of literature revealed that there are still many important research questions that need to be work out to confidently make use of the smart card data for ztOD application. The research questions are categorized as the conversion of stop level OD (stOD) to ztOD, transfer detection and couple of miscellaneous problems.