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21st Century Operations Using 21st Century Technologies

Disseminating Traveler Information on Travel Time Reliability

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United States Department of Transportation Federal Highway Administration

U.S. Department of Transportation
Federal Highway Administration
Office of Operations
1200 New Jersey Avenue, SE
Washington, DC 20590


January 2017


This document is disseminated under the sponsorship of the U.S. Department of Transportation in the interest of information exchange. The U.S. Government assumes no liability for the use of the information contained in this document.

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Table of Contents

List of Figures

List of Tables

Technical Report Documentation Page

1. Report No.
2. Government Accession No. 3. Recipient's Catalog No.
4. Title and Subtitle

Disseminating Traveler Information on Travel Time Reliability

5. Report Date

January 2017

6. Performing Organization Code:
7. Author(s)

Beverly Kuhn, Alan Pate, Laura Higgins, Robert Krile, Michael Vickich

8. Performing Organization Report No.
9. Performing Organization Name and Address

Battelle, 505 King Avenue, Columbus, OH 43201
Texas A&M Transportation Institute, 3135 TAMU, College Station, TX 77843

10. Work Unit No. (TRAIS)
11. Contract or Grant No.


12. Sponsoring Agency Name and Address

U.S. Department of Transportation
Federal Highway Administration (FHWA)
Office of Operations
1200 New Jersey Avenue, SE
Washington, DC 20590

13. Type of Report and Period Covered

Final Report 10/14-12/16

14. Sponsoring Agency Code


15. Supplementary Notes

Jimmy Chu, FHWA, Office of Transportation Management, Government Task Manager (GTM)

16. Abstract 16. Abstract

Travel time variability is that characteristic of the transportation system that means a traveler’s trip will vary from what is normally expected and will potentially take longer than planned. By helping travelers make travel choices that take into account travel time variability, agencies have the potential to reduce roadway congestion.

Travel Time Reliability (TTR) information includes static data about traffic speeds or trip times that capture historic variations from day to day and enable individuals to understand the level of variability in traffic. A key component to addressing the reliability issue related to urban mobility is conveying this TTR information to system users so that they can make informed decisions about their travel. The challenge for transportation professionals lies in selecting the best means of conveying that information so that it is usable and effective to the traveler and other stakeholders.

The Strategic Highway Research Program (SHRP2) Reliability Project L14 established a preliminary set of suggested terminology and guidelines for conveying TTR information to road users so that they may make optimal travel choices from their point of view, such as whether to take a trip or not, departure time, mode choice, and/or route choice. Specifically, a Lexicon of phrases was developed for each of eight TTR terms, which contained detailed guidelines for TTR information that would most likely be understood and used by travelers. To help agencies and other transportation-related entities better deploy and use the recommended Lexicon terminology, a field study was conducted to test the phrases to demonstrate the technical and institutional feasibility of their use and determine the potential costs and benefits of using these products of L14.

Overall, the field study found that the particular Lexicon phrases tested performed similarly. Only one survey question resulted in statistically significant differences between the Lexicon phrases. The biggest finding of the field study was that dissemination of TTR information via the 511 information channel was less preferred than via the Web or App access channels. In a few instances, the App access demonstrated superior responses over both the Web and 511 access.

17. Key Words

Travel time reliability, traveler information, arrival time, average travel time, buffer time, departure time, recommended departure time, recommended route

18. Distribution Statement

No Restrictions

19. Security Classification (of this report)


20. Security Classification (of this page)


21. No of Pages


22. Price

Form DOT F 1700.7 (8-72) Reproduction of completed page authorized

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