ASSESSING EXPECTED ACCURACY OF PROBE VEHICLE TRAVEL TIME REPORTS

The use of probe vehicles to provide estimates of link travel times has been suggested as a means of obtaining travel times within signalized networks for use in advanced travel information systems. Past research in the literature has provided contradictory conclusions regarding the expected accuracy of these probe-based estimates, and consequently has estimated different levels of market penetration of probe vehicles required to sustain accurate data within an advanced traveler information system. This paper examines the effect of sampling bias on the accuracy of the probe estimates. An analytical expression is derived on the basis of queuing theory to prove that bias in arrival time distributions and/or in the proportion of probes associated with each link departure turning movement will lead to a systematic bias in the sample estimate of the mean delay. Subsequently, the potential for and impact of sampling bias on a signalized link is examined by simulating an arterial corridor. The analytical derivation and the simulation analysis show that the reliability of probe-based average link travel times is highly affected by sampling bias. Furthermore, this analysis shows that the contradictory conclusions of previous research are directly related to the presence or absence of sample bias.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/oclc/8674831
• Corporate Authors:

  American Society of Civil Engineers

  1801 Alexander Bell Drive
  Reston, VA  United States  20191-4400
• Authors:
  • Hellinga, B
  • Fu, Liping
• Publication Date: 1999-11

Language

• English

Media Info

• Features: Appendices; Figures; References; Tables;
• Pagination: p. 524-530
• Serial:
  • Journal of Transportation Engineering
  • Volume: 125
  • Issue Number: 6
  • Publisher: American Society of Civil Engineers
  • ISSN: 0733-947X
  • Serial URL: https://ascelibrary.org/journal/jtepbs

Subject/Index Terms

• TRT Terms: Advanced traveler information systems; Arterial highways; Bias (Statistics); Estimating; Highway corridors; Network links; Origin and destination; Probe vehicles; Queuing theory; Sampling; Simulation; Traffic delays; Travel time
• Subject Areas: Highways; Operations and Traffic Management; Planning and Forecasting; Public Transportation; I72: Traffic and Transport Planning;

Filing Info

• Accession Number: 00778223
• Record Type: Publication
• Files: TRIS, ATRI
• Created Date: Nov 29 1999 12:00AM