An efficient General Transit Feed Specification (GTFS) enabled algorithm for dynamic transit accessibility analysis

• Published in: PloS one Vol. 12; no. 10; p. e0185333
• Main Authors: Fayyaz S., S. Kiavash, Liu, Xiaoyue Cathy, Zhang, Guohui
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 05.10.2017; Public Library of Science (PLoS)
• Subjects: Accessibility; Algorithms; Biology and Life Sciences; Computer and Information Sciences; Computer applications; Computing time; Ecology and Environmental Sciences; Engineering; Engineering and Technology; Environmental engineering; Functions (mathematics); Health aspects; Interoperability; Light rail transportation; Local transit; Mathematical analysis; People and places; Physical Sciences; Public transportation; Research and Analysis Methods; Smart cards; Software packages; Source code; Specifications; Transit; Transportation; Transportation networks; Transportation planning; Transportation systems; Travel; Travel time; Traveltime; Urbanization; United States > US
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0185333

The social functions of urbanized areas are highly dependent on and supported by the convenient access to public transportation systems, particularly for the less privileged populations who have restrained auto ownership. To accurately evaluate the public transit accessibility, it is critical to capture the spatiotemporal variation of transit services. This can be achieved by measuring the shortest paths or minimum travel time between origin-destination (OD) pairs at each time-of-day (e.g. every minute). In recent years, General Transit Feed Specification (GTFS) data has been gaining popularity for between-station travel time estimation due to its interoperability in spatiotemporal analytics. Many software packages, such as ArcGIS, have developed toolbox to enable the travel time estimation with GTFS. They perform reasonably well in calculating travel time between OD pairs for a specific time-of-day (e.g. 8:00 AM), yet can become computational inefficient and unpractical with the increase of data dimensions (e.g. all times-of-day and large network). In this paper, we introduce a new algorithm that is computationally elegant and mathematically efficient to address this issue. An open-source toolbox written in C++ is developed to implement the algorithm. We implemented the algorithm on City of St. George's transit network to showcase the accessibility analysis enabled by the toolbox. The experimental evidence shows significant reduction on computational time. The proposed algorithm and toolbox presented is easily transferable to other transit networks to allow transit agencies and researchers perform high resolution transit performance analysis.