What's missing from Australian household travel surveys? Off-peak travel!

When Veitch Lister Consulting (VLC) redeveloped its Zenith model of Victoria, we investigated any biases that might exist in the 2007 Victorian Integrated Survey of Travel and Activity (VISTA07). Simply put, a model estimated using a biased survey will itself be biased! We assigned the weighted survey data to the model transport network and compared the outputs to other observed measurements of travel demand such as traffic and person count data for various modes. VISTA07 accurately reflects peak period travel, especially in the AM Peak, but under-estimates travel during the remainder of the day, during both the inter-peak and off-peak periods. Unadjusted for, this could cause transport models to under-predict off-peak travel. To properly understand and adjust for this effect, we needed to understand its source, which could be: 1. under-reporting of travel by survey respondents; 2. sample bias not accounted for in the usual weighting method; 3. travel which is by definition not part of the VISTA survey, such as visitor travel, travel made by professional drivers and freight vehicles. To explore these causes, similar analyses were done in the Sydney Greater Metropolitan Area using the Sydney Household Travel Survey. Comparisons were made with trip purpose information from the Melbourne Rail OD survey, and we performed regressions using traffic counts. A significant amount of the “missing travel” during off peak periods may be related to work and tertiary education commuting, and not discretionary travel as we had previously thought. This indicates undetected sample bias which is not accounted for in the usual weighting method.

• Record URL:
  • http://www.atrf.info/papers/2013/index.aspx
• Authors:
  • Veitch, T
  • Paech, M
  • Eaton, J
• Conference:
  • Australasian Transport Research Forum (ATRF), 36th, 2013, Brisbane, Queensland, Australia
• Publication Date: 2013-10

Language

• English

Media Info

• Pagination: 19p
• Monograph Title: Transport and the new world city: 36th Australasian Transport Research Forum (ATRF), October 2nd-4th 2013, Brisbane

Subject/Index Terms

• TRT Terms: Accuracy; Behavior; Households; Mathematical models; Off peak periods; Travel; Travel behavior
• Geographic Terms: Australia; Melbourne (Australia); Sydney (Australia)
• ATRI Terms: Accuracy; Household; Modelling; Off peak hour; Travel behaviour
• ITRD Terms: 611: Off peak hour
• Subject Areas: Society; I72: Traffic and Transport Planning;

Filing Info

• Accession Number: 01514699
• Record Type: Publication
• Source Agency: ARRB
• Files: ITRD, ATRI
• Created Date: Feb 20 2014 10:13AM