Full-Day Accessibility Evaluation of Transit Systems Using GPS-Based Location Data

Principal Investigator(s):

Ying Song, Associate Professor, Geography

Project summary:

This project is utilizing the vehicle movement data collected within transit networks, exploring the spatio-temporal distributions of dwell times and other delays, and using them to improve the estimation of future arrival times. The aim is to use this information to provide more reliable service to transit users and refine existing multi-modal accessibility measures that consider traffic situations along transit routes throughout the day. Most transit system operators collect, store, and manage automatic vehicle location (AVL) and automatic passenger counter (APC) datasets, which are underutilized in research on how traffic affects transit system performance and the consequent users' transit mobility/accessibility. Conventional analyses usually extract the arrival and departure times at bus stops and/or rail stations from AVL and APC data and use them to model dwelling and average waiting times along routes. This omits the vehicle location data collected between stops or stations, and this can be valuable in understanding the behavior and impacts of a transit system. This project is working with AVL and APC datasets in their original formats and demonstrating how mobility and accessibility can be analyzed and modeled from a reliability perspective. Instead of assuming perfect schedule adherence every day, it will be possible to measure how much variation in mobility and accessibility users experience due to unpredictability in transit travel times. Additionally, this approach may reveal approaches to optimize transit system operations by identifying "hot spots" where and when transit performance is most impacted by road congestion. This project is designed in accord with the currently emerging sustainable mobility paradigm in transportation planning. It recognizes that expanding roads and increasing speeds are not sufficient to fulfill the increasing demands on mobility. Instead, such measures may result in more environment costs such as gas consumption, greenhouse gas (GHG) emissions, injuries, and traffic fatalities. Providing reliable and affordable transit services is a feasible solution that can reduce automobile dependency while improving access to housing, jobs, health services, and various resources and opportunities.

Project details: