COMPARISON OF OBSERVED AND CODED NETWORK TRAVEL TIME AND COST MEASUREMENTS

The paper compares two types of measurements of trip times: those provided by the standard network algorithms are compared with trip-time components observed along the traveler's path from home to work and back. The two types of measurements are found to be different. The root mean square errors of the network measurements with respect to observed values are very large (75-135 percent of the mean value) for the non-line-haul travel time components. The means and the variances of the network measured variables, as a rule, are much smaller than the variances or means of the manually coded observed-travel times. Coefficients estimated by using the two types of data are not numerically similar. Statistical tests show that at least the alternative-specific constants' and the level-of-service variables' coefficients are different in the models developed by using the two types of data. Finally, the effect of substantial errors in level-of-service measurements on travel forecasts is discussed. It is also shown that good (short-run) travel forecasts can be obtained from the network-based models provided that consistent network coding conventions are followed and incremental forecasts are avoided. (Author)

Media Info

  • Media Type: Print
  • Features: Figures; References; Tables;
  • Pagination: pp 46-51
  • Monograph Title: Travel behavior methodology
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00308565
  • Record Type: Publication
  • ISBN: 0309029732
  • Files: TRIS, TRB
  • Created Date: Apr 22 1980 12:00AM