Comparison of passengers' behavior and aggregate demand levels on a subway system using origin-destination surveys and smartcard data

Abstract

The purpose of this paper is to compare the information of origin-destination (OD) matrices, transfers and passenger load levels from two data sources for Metro de Santiago: OD survey and smartcard data. Using the OD survey data, it is possible to determine passenger loads and transfer flows for each line of the network, as the route of the surveyed trips, including transfer stations, is identified. Moreover, OD matrices can be estimated using smartcard data in Santiago's integrated transit system. The latter is done establishing the time and geographical position of every boarding transaction in the system using the GPS equipment inside buses or validation devices in subway stations. Using also an alighting stop estimation model, it is possible to determine the OD matrix. The estimated matrix is assigned in a transit equilibrium model, where passenger load levels are a result of this process. Both sets of demand levels show a strong correlation between them, which in the future would allow the use of smartcard data as the main source of information for the construction of OD matrices, avoiding the need to perform the complete OD survey. Anyhow, a smaller specific survey to address socioeconomic and accessibility data would be needed as a complement, saving considerable resources. This proposed methodology becomes crucial considering the important expansion that the Metro network will face by 2020; this is 37 km for two new lines and 6 km for two line extensions. These expansion projects will include 32 new stations, nine of them with transfer possibilities.