01500150

Monograph

http://www.trb.org/Main/Blurbs/169809.aspx

http://onlinepubs.trb.org...ity/FINALREPORTL15D%20.pdf

This project explored the use of commercially available consumer global positioning system (GPS) data in travel reliability studies. Specifically, two TomTom traffic data products, namely MultiNet and TrafficStats, which produce respectively time-of-day link travel speed profile and travel time statistics on selected routes and their segments, are considered. The quality of these two commercial data products is evaluated using GCM data, a publicly available traffic sensor database. There are several findings from the evaluation studies. First, TomTom speed profile data generate average travel time estimations for highway segments that match those from GCM data reasonably well. However, estimated average link travel times from TomTom are about 10%-15% lower than those from GCM data. Second, using TomTom data as a benchmark, the travel times on arterial streets are found to be severely underestimated in the GCM database. Third, the daily speed profiles obtained from TomTom and GCM data do not match very well on most expressways examined in this study. In general, TomTom data tend to underestimate the travel speed on highway segments. Fourth, the quality and usefulness of the data provided by TrafficStats raise more concerns. The percentile route travel time provided in the route reports seems to spread out too much and have a variance too high to be realistic in most cases. These percentile travel times also do not match the reported route segment statistics, especially in terms of variance. The conclusion of the research team is that the utility of this product has to be considered with cautions, especially given its high price. TomTom data provide a more reliable data source for arterial roads than the GCM database since it is based on real observation instead of statistical estimation. Reliable routing experiments show that the reliability routing results are changed significantly after TomTom data are used to generate travel time distributions on the arterial streets. The authors speculate that the main reason for this change is that the travel times for arterial streets in GCM were severely underestimated. As a result, many arterial-based paths that were found reliable for certain risk-taking preferences were no longer attractive because they become much longer when TomTom data are used. Based on the VNET platform, this project developed the RIDEA application, which integrates the functions to access and visualize the TomTom/GCM databases and to generate reliable routing guidance. RIDEA provides a prototype to support future commercial software development for travel reliability analysis.

This IDEA project was conducted by Northwestern University, Evanston, Illinois. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved

SHRP 2 Reliability IDEA Project L15D

English

56p

2013-10

SHRP 2 Reliability IDEA Program Project Final Report

Final Report

Print

Appendices; Figures; References; Tables

Arterial highways; Data quality; Databases; Global Positioning System; Real time information; Route guidance; Traffic data; Travel time; Urban travel

Innovations Deserving Exploratory Analysis (IDEA) (Program); TomTom

Travel time reliability

Data and Information Technology; Highways; Planning and Forecasting; I72: Traffic and Transport Planning

TRIS, TRB, ATRI

Nov 25 2013 11:42AM