Collecting representative household samples and their accurate travel and activity profiles can appropriately support national or regional transportation decision-making. Conventionally, a random-digit-dial (RDD) sampling method has been used for household travel surveys. However, due to the recent increase in mobile phone only households, an address-based (ADD) sampling method is alternatively considered. This presentation will provide an empirical comparison for socio-demographic characteristics of samples obtained in RDD and ADD household travel surveys, focusing on a common area of Northern Virginia: the 2009 National Household Travel Survey Add-On in Virginia (NHTS) and the 2008 National Capitol Region Household Travel Survey (NCRHTS), respectively.

Also, this presentation will compare travel behavior captured in the two surveys. While both surveys collected data through the computer-assisted telephone interviewing method, their respective survey instruments were quite different. The NHTS used a comprehensive survey instrument including attitudinal and socio-demographic questions as well as a travel diary. In comparison, the NCRHTS instrument was more concise and focused on, collecting behavioral data on key variables for the regional travel demand model. This research developed rigorous statistical models to quantify the differences in results between the two surveys. Differences were calculated in terms of the number and the length of daily trips for each trip mode between the two surveys.

This presentation will discuss the results of the statistical comparison as well as advantages and disadvantages of the two survey methods, which can provide valuable insights to assist with future regional and national survey implementations. Furthermore, the findings can support non-motorized transportation research and better decision-making in transportation planning.