Improving Survey Methods Using a New Objective Metric for Measuring Driving Time Variability in Survey and GPS Data

Accurate estimates of day-to-day variability in driving times are of critical importance for many travel-related issues: predicting traffic congestion from past traffic patterns, estimating emissions, and estimating relative crash risk compared to baseline driving exposure. Driving times based on survey data necessarily rely upon subjective recall as obtained in daily diaries, interviews or phone surveys. Within the last few decades, objective GPS data have become available in travel studies carried out in many major cities in the U.S. and other countries. Few studies to date have compared GPS and survey data for the same subjects on the same day of travel, and even fewer studies have collected both GPS and survey data for more than one day of travel. This paper proposes a new objective metric for comparing GPS and diary data either on the same day or across multiple days that does not require trip matching, thereby improving accuracy of both GPS and survey methods for estimating day-to-day variability. The proposed metric allows an objective measure for within- and between-day comparisons between survey and GPS methods, as well as estimating day-to-day variability in driving times within survey and GPS methods. This new metric may improve reliability and accuracy of both survey and GPS estimates of day-to-day driving consistency.


  • English

Media Info

  • Media Type: Digital/other
  • Features: Figures; References;
  • Pagination: 16p
  • Monograph Title: TRB 91st Annual Meeting Compendium of Papers DVD

Subject/Index Terms

Filing Info

  • Accession Number: 01370341
  • Record Type: Publication
  • Report/Paper Numbers: 12-4086
  • Files: TRIS, TRB
  • Created Date: Feb 8 2012 5:21PM