Trade-offs Between Inductive Loops and GPS Probe Vehicles for Travel Time Estimation: Mobile Century Case Study

This article addresses the trade-offs between (i) velocity data collected from GPS smartphones in probe vehicles, and (ii), velocity data obtained from inductive loop detectors, for the purpose of computing travel times on a stretch of roadway. It is a case study which uses experimental data collected on one day in the San Francisco Bay Area, obtained as part of a 2008 field experiment known as Mobile Century. Estimates of the traffic velocity field are constructed using a velocity model equivalent to the Cell Transmission Model, and a traffic state estimation algorithm known as ensemble Kalman filtering. More than 900 combinations of inductive loop detector data and GPS data of various data volumes are considered. Instantaneous and a posteriori dynamic travel times are computed by integrating the estimated velocity field, and are compared to travel times recorded using license plate re-identification. Key findings include (i) dynamic travel time estimates can be computed with less than 10% error using only probe data, only inductive loop data, or a mixture of inductive loop and probe data (ii) by combining loop detector data with probe vehicle data, better estimates for travel times are obtained especially when loop data or probe data is sparse.

• Supplemental Notes:
  • This paper was sponsored by TRB committee ABJ30(3) Travel Time, Speed and Reliability
• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Mazaré, Pierre-Emmanuel
  • Tossavainen, Olli-Pekka
  • Bayen, Alexandre
  • Work, Daniel B
• Conference:
  • Transportation Research Board 91st Annual Meeting
  • Location: Washington DC, United States
  • Date: 2012-1-22 to 2012-1-26
• Date: 2012

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; References; Tables;
• Pagination: 19p
• Monograph Title: TRB 91st Annual Meeting Compendium of Papers DVD

Subject/Index Terms

• TRT Terms: Global Positioning System; Kalman filtering; Loop detectors; Probe vehicles; Travel time; Velocity
• Geographic Terms: San Francisco Bay Area
• Subject Areas: Data and Information Technology; Highways; I71: Traffic Theory;

Filing Info

• Accession Number: 01366475
• Record Type: Publication
• Report/Paper Numbers: 12-2746
• Files: TRIS, TRB
• Created Date: Mar 29 2012 7:14AM