National Household Travel SurveyData User Tools
Adella Santos
FHWA-OFFICE OF HIGHWAY POLICY INFORMATION
APDU 2008 ANNUAL CONFERENCE
SEPTEMBER 25, 2008
Today’s Presentation
• Public data: Purpose for Planning and Policy
• About the NHTS Data
• Travel Trends
• Data Content and data sets
• Uses and Users
• Data Products and User data Tools
About the NHTS Data…
• National Study on travel of the American Public• Add-On Program for States and metropolitan
areas.• 40 Years of Travel Data
– 1969, 1977, 1983, 1990, 1995, 2001, 2008• Link between demographics, travel and
vehicles.• Widely used inside and outside the
transportation research, planning and policy communities.
Planning and Policy: How do we get from here to there?
• v
Use of a travel diary
What do we ask? Core Travel Data Content
• Household demographics (composition and income)• Person (Age, race, sex, ethnicity, worker & students
status, citizenship, education)• Geography (urban, rural, suburban, state and national
analyses) • Vehicles (Make, model, year, mileage alternative fuels)• Trips/Commute information (mode, occupancy, time
of departure, purpose, work location and occupation, distance trip length)
For Each Household:Number of peopleNumber of driversNumber of workersNumber of vehiclesIncomeRace and Ethnicity
For Each Vehicle:Make (Hybrid/Alternative fuel)Model Age (year)How long owned*
For Each Person:Age GenderDriver statusWorker StatusAnnual Miles
Daily Travel Data:PurposeModeStart/End timeDistanceVehicle OccupancyInterstate use
Travel Data Depends on:
Trends in Travel Content: 2008 New and Improved Data
Shopping by Internet and deliveries to the household
Frequency of self-employed and work at home instead of traveling to workplace
Flexibility of arrival time at work Vehicle Make and model, whether hybrid or alternate fuel used
Travel to school detail to support Safe Routes to School program
Whether trip included travel on freeway/interstate and whether a toll was paid
Internet shopping and the impact of purchases being delivered
In 2001 we started to see a relationship on internet use and travel…
Figure 7 - Minutes per Day Spent in Visiting Friends and Shopping, 1995 and 2001
Time Spent at Destinations by Purpose, 1995 and 2001
0.05.0
10.015.020.025.030.035.040.0
Time atVisit
Time atShop
Time atVisit
Time atShop
Time atVisit
Time atShop
16-30 31-45 46-60
Sum
of
Min
utes
per
day
--al
l trip
s
1995 2001 2001 Internet High Users
Source: Contrino and McGuckin paper to be submitted TRB 2008
Other sources show increased household purchases on-line…
0
0.2
0.4
0.6
0.8
1
1.2
2000 2001 2002 2003 2004
Year
Avg
. # P
urc
hase
s/H
H
Source: USPS HDS data
Average Number of On-Line Purchases per Month
What are the effects on system use?
More Truck in Residential areas:•Congestion impacts•Safety Issues•Economic impacts
Trend Issue: Fleet Penetration and use of Hybrid/Alternative fuel Vehicles
Since 1969 we have collected fleet characteristics (make/model/age of vehicle)
Since 2001, added value of vehicle efficiency (mpg) and gas cost
2008, added Hybrid and alternate fuel use
Fleet Characteristic and fuel cost are changing
Percent of Household Vehicles
Average MPG*
Cost per Mile in 2001
Cost per Mile in 2006
Car 59.9% 22.4 6.3 cents 14.1 centsVan 9.4% 18.4 7.5 cents 16.6 centsSUV 12.5% 16.7 8.2 cents 18.4 centsPick-Up 18.2% 16.9 8.3 cents 18.3 cents
Overall 100.0% 20.3 7.0 cents 15.6 cents* Fuel Efficiency Provided by the Energy Information Agency
The Average Vehicle is 9 Years Old.
6.6
7.6 7.7
8.3
8.9
0
1
2
3
4
5
6
7
8
9
10
1977 1983 1990 1995 2001
Source: NHTS Data Series, 1977 - 2001
NHTS 2001 and 2008 Data Sets
2001 NHTS
- Household data set: 69,817 records, 188 variables
- Person data set: 160,758 records, 142 variables
- Daytrip data set: 642, records, 150 variables
- Vehicle data set: 139, 382 records, 92 variables
- 3 replicate weight files: each has 398 variables
- Contains 239 derived variables.
2008 NHTS • - 150,000 Households (25,000 national Sample and
125,000 Add-On sample).
Major Users and Uses
Users
• Federal (DOT)• Federal (Non DOT)• State DOT• MPOs• Universities• Research Entities
Uses
• System Use Measures (congestion, Urban/rural)
• Travel Characteristics (Trends & Forecasting)
• Mode Use for Transit Planning, Bike/Pedestrian,
• Safety (Exposure rates)
Other Measures
• Provides data for forecasting and air quality analysis.• Tracks changes in fleet characteristics and use (e.g.
Hybrids vehicles and effects of rising gas prices on travel)• Marks the effect of new technology/uses on travel
behaviors (e.g. internet shopping and deliveries to homes.)
• Policy effects in Travel (e.g. work at home workers with flexible arrival time.)
• Rich in Demographics (e.g. travel demands specific population groups such as immigrants, elderly, school children, low income)
NHTS Products
PUBLICATIONS:• Policy Briefs• State Profiles• Summary of Travel Trends• Our Nation’s Travel: Current Issues
Data Trends Data Set: 1990, 1995, 2001
Data Tools• NHTS Website: http://nhts.ornl.gov (Community
of exchange) • On Line Analysis Tool• Transferability Tool
NHTS Policy Briefs
State Profiles
NHTS Website: http://nhts.ornl.gov.
Please visit our website: http://nhts.ornl.gov
Transferability Data Tool
Accessing NHTS Products
• State Profiles
• Summary of Travel Trends and Our Nation’s Travel: Current Trends
• Trends Database: CD
• Policy Briefs: http://ornl.gov/publications.shtml#issueBriefs
• Transferability
– http://fmip.ornl.gov/nhts/
• On-line Analysis Tool: http://nhts.ornl.gov
– SAS Data Set: http://nhts.ornl.gov/download.shtml