Examining the Role of Trip Length in Commuter Decisions to Use Public Transportation
Yao Yu and Randy Machemehl, University of Texas at Austin, June 2010, 45 pp. (476660-00074-1)
Traveler trip length has for years been used as a fundamental indicator of the best mix of transit modes and user perceptions of travel cost for transit versus auto. This study examines traveler trip lengths across transit modes, work trip duration frequency distributions and mode share distributions in 7 major cities, 8 Combined Statistical Areas and one Metropolitan Statistical Area and found the effect of increasing population and transit mode variety on work trip travel time and travel distance.
A traditional hierarchy of transit modes arranged by traveler trip length might include local bus, light rail, rapid rail (heavy rail) and commuter rail (regional rail). Based on NTD data, the average trip length for these four modes are: local bus (4.6 miles), light rail (3.9 miles), heavy rail (6.3 miles), and commuter rail (30.1).
Trip Time Frequency Distributions for home-based work trips in all major cities selected in this study followed the same pattern except in New York, NY. In virtually all cities from 1990 to 2005, frequencies decreased in all categories less than 30 minutes and increased in categories greater than 30 minutes. Meanwhile, Trip Time Frequency Distributions for home-based work trips in all selected MSAs also followed the same pattern. These results contradicted our assumption that cities or MSAs with different urban forms or transit history might have different Trip Length Frequency Distributions (TLFDs) and showed that at an aggregated level, there is no statistically significant difference among TLFDs for work trips in the selected areas.
Average work trip length for all the 50 MSAs in National Household Travel Survey data also showed that travel time and travel distance for home-based work trips in all selected MSAs are very similar. Also, from the linear regression functions with trip length as dependent variable, it can be seen that work trip time and distance tend to increase with increasing population, work trip time and distance tend to increase also as the number of transit modes increase.
Keywords: Trip Length, Travel Time, Travel Distance, Work Trip Duration, Transit Modes
SUMMARY REPORT (Adobe Acrobat File – 3.4 MB)