Travel and Congestion Survey

Welcome to the Travel and Congestion Survey Web page. The Travel and Congestion Survey was completed in 2003 and will be used to support transportation model improvements for the next Regional Transportation Plan and other transportation studies. What follows are answers to most commonly received questions.

Frequently Asked Questions

Q: What is the Travel and Congestion Survey?
A: It is a survey of the daily travel habits of households within six counties of Southern California (Imperial, Los Angeles, Orange, Riverside, San Bernardino and Ventura). For the sake of simplicity, we will refer to it simply as "the Survey". The survey was conducted primarily in the 2001 and first half of 2002, though portions of the survey were finalized in 2003.

Q: Who conducted the travel survey?
A: The Southern California Association of Governments (SCAG) contracted Nustats, a nationally recognized research firm, to conduct the travel survey. The survey was funded by SCAG, the LACMTA, Caltrans, RCTC, SanBAG and the California Air Resources Board.

Q: What is the survey used for?
A: The survey will help the agencies responsible for planning and improving roads, carpool lanes, trains, buses and other features of our transportation system. It will shed light on how that system is being used and by whom. For example, electronic sensors can tell you the condition of your favorite freeway; but only through travel surveys do we get a sense of how many freeway trips are destined to nearby supermarkets, or perhaps to distant places of work. Transit agencies, likewise, use travel surveys to plan bus service between popular places.

Q: How often is a travel survey conducted for the entire region?
A: Surveys of this magnitude are conducted about every ten years. The last survey was conducted in 1991. The next travel survey is not anticipated until after the year 2010.

Q: How many households were part of the survey?
A: The survey encompassed over 20,000 households.

Q: How were households chosen to participate?
A: Households were selected by random drawing. Random selection allows us to make statistical inferences about all five million households in Southern California (excluding San Diego). Each sampled household represents over 250 other households.

Survey as Public Information Source

Q: What kind of information will be available to the public?
A: Main Survey Final Report. This document summarizes key travel statistics such as trip rates, mode of travel and average travel times.

Q: I am a researcher. What additional data is available to support my transportation research?
A: SCAG has released trip tables with origins and destinations assigned to census tracts.

Q: Who can I contact to for trip tables?
A: Contact Mansoureh Jeihani at SCAG, (213) 236-1938 or email jeihani@scag.ca.gov

Survey as Data Source for Transportation Demand Model Improvement

Q: How will the survey improve transportation demand modeling?
A: The survey relates to each of the standard four modeling steps:

  • Trip Generation: Update trip rates for various trip types (work, shopping, etc.)
  • Trip Distribution: Update travel impedance's and peaking factors
  • Mode Choice: Will refine utilities for transit and car pool modes?
  • Assignment: The survey will permit distribution of trips by time-of-day. The GPS portion of the travel survey will be used to validate the use of Caltrans PEMS data for improvements to travel speed estimates.