Improving Quality and Accuracy in Select Travel Surveys

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D.F. Pearson, E.N. Hard, S.P. Farnsworth, T.L. Forrest, D.L. Spillane, M.I. Ojah, K.N. Womack, S.A. Boxill, C.A. Lewis

Publication Date:

November 2009


This project summary report summarizes the research performed in Texas Department of Transportation (TxDOT) Project 0-5711. The TxDOT Transportation Planning and Programming Division (TPP) funds and manages an ongoing statewide travel survey program. This program collects data on travel in all major urban areas in Texas. Two elements of this program, household and external travel surveys, are critical in the efforts of the department to develop and maintain travel demand models that accurately reflect travel behavior in Texas. This project examined these surveys in respect to issues such as non-response, sampling frame, proxy reporting, sample size, directionality, time of day, and quality control. The objective of the research was to evaluate the impact of data quality and accuracy. Researchers performed an extensive review of the literature and survey practice in areas outside Texas, and evaluated data from recent household and external travel surveys in Texas. An additional evaluation was conducted on the accuracy of automatic vehicle classification counters relative to their use in external surveys and vehicle classification counts. Based on the research findings, researchers developed a guidebook on quality control of household and external surveys. This research found that the household and external surveys within the overall travel survey program produce high-quality data that ensure the TxDOT travel demand models accurately reflect overall travel within Texas urban areas. A number of recommendations from this research may be implemented to improve the data and maintain the high quality of the travel surveys.

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