Bureau of Transportation Statistics

1
An Analysis ofPreliminary NHTS ResultsBefore
and After September 11

• TRB Committee Meetings
• January, 2005

2
2001 National Household Travel Survey

• 60,000 individuals in 26,000 households
• 45,000 long distance trips
• Collected March 2001 to May 2002
• Telephone survey
• Nationally weighted results

3
Long-Distance TravelSurvey Results

• Estimated 2.6 billion long-distance trips in 2001
• 90 percent by privately owned vehicle (POV)
• 7 percent by air
• 2 percent by bus
• 1 percent by other

4
Outline

• What we did
• What we found

5
Post 9/11 Pattern Changes

• Decrease in international trip taking
• Reduction in discretionary travel
• Lower percentage of trips by persons under 25
• Changes in travel by mode depending on distance
  traveled
• Note The findings we present are all
  statistically significant at the 95 level of
  confidence

6
Creation of Pre 9/11 Post 9/11 Files

• The 2001 NHTS file were divided into two parts
• Divided based on person data, not trip data
• Long-Distance trips covered a 4 week period for
  each person
• The few trips that overlapped 9/11 were deleted

7
Limitations of the NHTS Data

• Before and after data collection periods are not
  equivalent
• NHTS trip numbers are not adjusted for
  seasonality
• Economic factors before and after 9/11 could
  affect number of trips

8
Lower Percentage of International Trips After
9/11
9
Lower Percentage of Personal Business Trips After
9/11
10
Lower Percentage of Trips by Persons
Age 24 or Younger After 9/11
11
Percent of Trips For All Modes
12
Travel to Same or Different Census
Districts
13
Additional Bus Changes After 9/11
14
Where We Go From Here?

• Phase 2 More Detailed Report Bringing In Other
  Data Sources
• Time Series Analysis- Exploring Seasonality
• Analysis of Variables that Effect Economy

15
Contact Information

• U.S. Department of Transportation
• Bureau of Transportation
• Office of Advanced Studies
• ivy.harrison_at_bts.gov
• 202-366-5235