The National Household Travel Survey

Heather Contrino US Department of TransportationFederal Highway Administration

Office of Highway Policy Information

Outline of Today’s Presentation

About the NHTS Methods and Data Data Applications NHTS Products and Tools

About the NHTS

About the NHTS…

Only national data source on travel demand and travel behavior of the American public.

Measures travel by US households for all modes and all purposes

Survey conducted since 1969

The NHTS obtains information on the public’s use of the transportation system

Passenger Travel82%

Freight14%

Commercial Drivers4%

Highway Statistics, 2001

Highway StatisticsTotal VMT

(000,000s)

2,781,462

Highway StatisticsPassenger Travel

2,282,890

NHTS 2001 VMT 2,281,863

The NHTS Program – Two Components

National Study Serves the department, congress, and

administration Sample size of 25,000 households

Add-On Program Allows States and MPOs to purchase additional

samples for their local area Program participation has doubled every survey

year(Sample size of 125,000 households for 2008)

NHTS Program Structure

NHTS Program

National Study

n = 25,000List Assisted RDD

Add-On Program

n = 125,000List Assisted RDD

Some Additional Questions

Cell Only n = 1,250National coverage

2008 Add-On Program Participants

125,000 Add-On Samples

Florida DOT

Georgia DOT

South Carolina DOT

North Carolina DOTPiedmont Region

Virginia DOT

New York State DOT

Indiana DOTOmaha, Nebraska

Cedar Rapids, IAIowa DOT

Maricopa, AZPima, AZ

California DOT

Wisconsin DOT

Tennessee DOT

Texas DOT

South Dakota DOT

Vermont DOT

NHTS Add-On Program Benefits

What We Get Leadership in household travel survey data Larger program, visibility, stakeholders and users Greater analysis power

What They Get Administrative Functions (program management,

contracting, and quality assurance) Comparability Legitimacy Partnership

NHTS Program Features

Adding questions – each Add-On allowed five additional questions

Sample plan – area specific sample plans (within the constraints of overall sample methodology)

Quality Assurance – On-line access to status reports and monthly progress reports to Add-Ons

Study Design and Data

Study Design

National list assisted RDD with CATI Population of interest - US Households

with telephones Advance letter with incentives Multi-stage design

Advance Letter

Household Recruitment Diary Mailing

Travel Data Retrieval

Study Design (continued)

Single day travel period for all household members age 5+

All trips by all modes of travel, including walk and bike and access and egress modes

NHTS covers all days of the year with day of week and month of year balance

Study Design - New for 2008

Minimum State samples (n=250) Cell Phone only sample Add-On specific questionnaire content New data items for national study Improvements in weighting and

adjustments

NHTS uses a classic travel diary as a memory jogger…

At the beginning of my travel day (4:00 a.m.) I was: Home Some other place

WHERE did you go?

(Name of place)

What TIME did you start and end each

trip?

WHY did you go there?

HOW did you travel?

How FAR was it?

Started at: Arrived at:

(blocks or miles)

EXAMPLE:

West Park Theater2:00 p.m. 2:55

p.m.

To see a movie walk, bus, walk

6 miles

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

And obtains trips from one address to another by all modes…

01/17/01

Please remember, a trip is whenever you go from one address to another. OMB Nos.: 2139-0008; 2125-0545 Have this travel diary by the phone when the interviewer calls. You do not need to mail the diary back to us. Thanks Expiration date: xx/xx/xx

Example of Trips on a Travel Day

Trip 2 Walk Work

Home

Trip 4 Walk, subway, car

Lunch at Restaurant

Trip 5 Car

Trip 6 Car

Grocery store

Daycare center

Trip 1 Car, subway, walk

Trip 3 Walk

NHTS links households, people, vehicles, and trips…

NHTS Core Data Content Households

Income, composition, location

Persons Age, sex, race, ethnicity, worker and student status, citizenship,

education

Geography High level geography – urban, rural, suburban, state and national

analyses

Vehicles Make, model, year, mileage, alternative fuels, commercially licensed

Trips Mode, time of day, purpose, vehicle occupancy, distance, trip length

Major ContributionLinkage between people,

travel and vehicles

New 2008 NHTS Content

Congestion Interstate use and tolling Telecommuting – opportunity and frequency Work arrival time and flexibility

Safety Safe Travel to School Travel impacts of disability

Energy and Environment Shopping by Internet and deliveries to the household Hybrid/Alternative fuel vehicles Fuel costs by vehicle type and travel behavior Vehicle age, odometer reading, and annual mileage

Alternative Modes Access (to transit) travel party size Frequency of walk and bike Motorcycle ownership and use

Data Applications

Trend Data - There has been amazing growth in travel since 1969

Growth in Travel and Related Issues, 1969 - 2001

-100%

-50%

0%

50%

100%

150%

200%

250% Persons Households Person Trips Person Miles

Vehicle Trips Vehicle Miles Road Miles Annual Fatalities

N0x Emmission C0 VOC

Base: NHTS series since 1969

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

All Men Women

Trips/Person 1995Trips/Person 2001

Base: NHTS data series, travelers 16+

Travel Demand – But in the last decade, total trips have leveled off…

Congestion - Non-work Travel Adds to Peak Period Congestion

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000

1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11

Start Hour

Pe

rso

n T

rips

in M

illio

ns

Commute Fam/Pers (inc. Shop) School/Ch Soc/Rec

Mobility and impacts on access and travel options

This is the daily range of

travel for a low-income

African American

This is the daily range of

travel for a high income

African American

NHTS is used to develop daytime populations for security research…

Source: 2001 NHTS, Nate Erlbaum, NY DOT

Number of workers at

work, visitors, people in

motion and people at home

2:00 pm Tuesday

Memphis, TN

And for special studies… (example Florida DOT)

Hurricane Evacuation Planning Weekend and Holiday Travel Planning Seasonal Resident Impact

Broward County, Florida

Source: ACS 1999-2002, U.S. Census Bureau

Legend

SeasonalSEASONAL_1

No

Yes

Changes in population growth effect transportation demand

Top Ten States in Pct Growth of VMT to 2050

0.0% 20.0% 40.0% 60.0% 80.0% 100.0% 120.0%

Virginia

Oregon

Washington

Georgia

North Carolina

Idaho

Utah

Texas

Florida

Arizona

Nevada

Estimated on current VMT/person from NHTS and Census population forecast

0

100

200

300

400

500

600

2000 2010 2020 2030 2040

Ann

ual M

iles

in B

illio

ns

Men Women All

The driving population is aging…

Projections show a doubling of VMT by 2040 for drivers aged 65 and over

Base:Census projections and VMT/person from NHTS 2001

Which has safety implications as older drivers are more likely to be in a fatal accident…

0

2

4

6

8

10

12

16-19 20-24 25-29 30-34 35-39 40-44 45-49 50-54 55-59 60-64 65-69 70-74 75-79 80-84 85+

Num

ber

of A

nnua

l Fat

aliti

es p

er 1

00 m

il. V

MT

Base: NHTS data on driver miles by age and FARS fatalities

Reliable data on walk trips…

0

50

100

150

200

250

300

National NE Census Region NYCMSA

Minutes in Walk per capita Miles in Walk per capita

Which are used for Safety

Planning… Pedestrian Fatalities per Mile of Exposure

Source: 2001 FARS pedestrian Fatalities and NHTS 2001 miles walked

And to help understand the link between transportation and health:

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000

16,000

No Car 1 Car 2 Cars 3 Cars

VM

T P

er D

rive

r

Is increased vehicle use related to reduced walking and biking?

Mode Share to Walk/Bike VMT Per Driver

0

5

10

15

20

25

30

35

40

No Car 1 Car 2 Cars 3 Cars

Mo

de

Sh

are

to W

alk/

Bik

e

Source: Matt Coogan

0.0 20.0 40.0 60.0 80.0

African-Amer

Hispanic

White

Percent

Percent of Workerswho Took Transit toWork

Percent of Workerswith Workplaceswithin .25 miles of aBus Line

Percent of PopulationResiding within .25miles of Bus Line

Transit planners can use NHTS to understand who uses transit…

Shop/Errands23%

Visit/Soc18%

School/Church12%

Other12%

Work35%

Percent of Transit Trips by Purpose

And how transit is used:(not just commuting)

Based on current VMT per vehicle:Pct Decrease

(Impact)

Base Case (Current Est.) <null>

If 20% of vehicle fleet were hybrid (55 mpg) 2.5%

If fuel efficiency were raised 10% for all vehicles 9.1%

If all Vans, SUVs and P-U were replaced by cars 11.6%

If fuel efficiency were raised to 29 mpg for all vehicles 31.7%

If we doubled fuel efficiency in each vehicle class 50.0%

‘What if’ scenarios for climate change:

Source: McGuckin’s analysis based on NHTS 2001

And cold and hot starts for air quality analysis:

Vehicle Starts, Trip Lengths by Time of Day and Vehicle Utilization

Source: 2001 NHTS, Nate Erlbaum, NY DOT

We also include and track gas costs in our dataset:

Percent of Income Spent on Gasoline in Daily Household Travel, 2001 and 2006

0.0%

5.0%

10.0%

15.0%

20.0%

25.0%

30.0%

<10K $10-20K $20-30K $30-40K $40-50K $50-60K $60-70K $70-80K $80-100K

$100K+

Pct of Income Spent on Gas 01 Pct of Income Spent on Gas 06

Which allows us a unique perspective on the economics of travel:

$0.00 $0.50 $1.00 $1.50 $2.00 $2.50

CAR

VAN

SUV

P-U

CAR

VAN

SUV

P-U

CAR

VAN

SUV

P-US

ho

pp

ing

So

cia

l/Re

cW

ork

Cost for an average trip, 2006

NHTS Status and Schedule

2008 NHTS Schedule

Data collection completed – April 2009 Final weighted data file – October 2009 Public Use file – January 2010 Methods Research (for next NHTS) and

work for reauthorization is ongoing

Future Design Goals

Methods Coverage and Response Rates

Cellular phones and non-contacts

Periodicity Real time reporting environment Continuous study design/annual reporting

Relevant Content Establishing regular, reliable performance measures Maintaining trends while addressing new policy and

planning questions

NHTS Program Goals

Institutionalize the Study Specific program authorization and regular funding cycle

Maintain Add-On Program Regular State and MPO participation – federal, local and

community gains Serve User Community

Clear link to policy and planning questions National and State travel indicators On-line Analyses

Annual reporting of Key Measures Modeling and data integration to provide annual estimates Annual/continuous data collection Feed into performance measurement, annual reporting to

Congress (C&P), and other data programs (e.g. FARS)

NHTS Products and Tools

NHTS Products State Profiles Policy Briefs Trends Database Transferability On-line Analysis Tool Risk Assessment Tool

AAA Traffic Safety Foundation

NHTS

TrendsCD-ROM

Policy Briefs

State Profiles

NHTS Website

On-line Analysis Tools

Table Designer Tool

Local Area Estimation

Accessing NHTS Products

State Profiles Policy Briefs: http://ornl.gov/publications.shtml#issueBriefs

Trends Database: To be posted soon

Local area estimation:

http://fmip.ornl.gov/nhts/

Risk Assessment Tool:

http://www.aaafoundation.org/trafficSTATS/

On-line Analysis Tool: http://nhts.ornl.gov

SAS Data Set: http://nhts.ornl.gov/download.shtml

Contact Heather Contrino, FHWA

Thank You!Heather Contrino

Heather.Contrino@dot.gov