| Article ID: | iaor19972407 |
| Country: | United Kingdom |
| Volume: | 31A |
| Issue: | 3 |
| Start Page Number: | 259 |
| End Page Number: | 262 |
| Publication Date: | May 1997 |
| Journal: | Transportation Research. Part A, Policy and Practice |
| Authors: | Gordon Peter, Richardson Harry W., Liao Yu-Chun |
| Keywords: | statistics: inference |
This note challenges the use of census data for evaluating changes in commuting speeds, partly because these data require indirect distance measures, but primarily because they do not differentiate between non-stop trips and trip chains. The proportion of trip chains to total trips increased between 1983 and 1990 (Nationwide Personal Transportation Survey). Hence, results of declining speeds based on census data may be spurious. When trips are broken down by type using Nationwide Personal Transportation Survey data, speeds increased between 1983 and 1990 for all categories, in all but one of eight cases studied, by significant amounts.