Download Public transport OD matrix estimation from smart card payment

Public transport OD matrix estimation from smart card payment system data
Marcela A. Munizaga
[email protected]
Departamento de Ingeniería Civil, Universidad de Chile. Casilla 228-3, Santiago, Chile
Nowadays, many cities in the world have incorporated information technology to their public
transport systems. Santiago, Chile is not an exception, and the new public transport system
Transantiago has introduced GPS bus location and a smartcard payment system that provide an
excellent opportunity for passive data collection. This is a rather new system, implemented only in
2007, and one important characteristic of the new system is that a very high percentage of the
boardings are recorded in a huge Transactions database, and a significant percentage of users that
use the same card in all his/her trips (transactions). This characteristic, which is not present in
other public transport system, represents an excellent opportunity for public transport planners,
as we can follow cards (users) through the system, and identify their travel patterns. This source of
information has so much space-time detail that permits analyzing not only mean attributes at any
desired level of time-space disaggregation, but also variance and regularity of behavior. In this
paper we describe the data and some of the potential applications, and show some preliminary
results. We focus on OD matrix estimation. We propose a method to estimate boarding and
alighting bus stops, and to estimate travel time and time assigned to activities between trips. The
proposed method is applied to the database of one week of system operation that contains near
40 million observations. The results are analyzed in terms of variance and reliability. Furthermore,
we explore on the issue of potential biases that could affect the estimation of an OD matrix from
this information.