NHTS OMB Final

SUPPORTING STATEMENT

National Household Travel Survey

This is to request OMB approved clearance for the previously conducted National Household Travel Survey (formerly the NPTS) which has been conducted since 1969.

Part A. Justification

1. Circumstances that make collection of information necessary:

The NHTS is the U.S. Department of Transportation’s only inventory of passenger travel. The data are used to determine current travel characteristics, such as the relative proportion of travel by mode (e.g. vehicle, transit, and walk) and purpose (e.g. work, school, family/personal, and recreational) by residents of U.S. households. These data allow the Department to evaluate the adequacy of existing transportation facilities and estimate future needs. The NHTS is consolidated with other data to provide a bi-annual report to Congress.

In addition, data from the NHTS serves to answer important questions from the Secretary’s office, Congress, State and local Department’s of Transportation, researchers and the media on current characteristics of travel by the American public, including:

• Factors which affect the use of private vehicles, carpooling, and alternative modes,

• The use of the transportation system by demographic groups to determine mobility barriers, the rate of accidents and fatalities (exposure and risk analysis), and travel demand,

• Development of performance measures to evaluate system stresses, such as congestion measures,

• Evaluation of potential planning and policy initiatives,

• Travel behavior benchmarks for local and regional planning agencies, and

• The public’s view of the adequacy of transportation systems and services.

Title 23 United States Code, Section 502 authorizes the Department of Transportation (DOT) to carry out advanced research and transportation research to measure the performance of the surface transportation systems in the United States, including the efficiency, energy use, air quality, congestion, and safety of the highway and intermodal transportation systems. The DOT is charged with the overall responsibility to obtain current information on national patterns of travel, which establishes a data base to better understand travel behavior, evaluate the use of transportation facilities, and gauge the impact of the department's policies and programs.

The NHTS is an established core program for DOT. 2008 NHTS will be sixth in the data series, and will provide up-to-date information on national patterns of travel. The previous surveys were conducted in 1969, 1977, 1983, 1990, 1995, and 2001. The 2008 survey will update the information on demographics and travel patterns, providing almost 40 years of national trend data. The continuity of the data series is important in identifying and assessing travel trends.

Within DOT, the Federal Highway Administration (FHWA) has responsibility for technical and funding coordination. Other agencies, including Federal Transit Administration (FTA), National Highway Safety Administration (NHTSA), and the Bureau of Transportation Statistics (BTS), have historically provided funding support and input to the survey content and planning.

2. How, by whom, and for what purpose is the information used:

The NHTS is designed primarily to obtain data needed for performance measurement, policy analyses, program planning, and program management by agencies within the Department of Transportation (DOT): the Office of the Secretary (OST), Federal Highway Administration (FHWA), the Federal Transit Administration (FTA), the National Highway Traffic Safety Administration (NHTSA), and the Bureau of Transportation Statistics (BTS).

The NHTS provides data not available from any other source, and has a widely disparate user community. Other Federal agencies depend on the NHTS data, for instance the Department of Energy (DOE) uses the data to estimate residential transportation-related energy use, the Environmental Protection Agency (EPA) uses the data as an input to the standard air-quality estimation model, and the Centers for Disease Control (CDC) use NHTS to assess the connection between transportation choice, land use, and health. State and local transportation agencies and transit authorities use the data for benchmarking local statistics and to examine trends in use. The data is also widely used by a range of researchers and public and private agencies, for example the Transportation Research Board, Highway Users Federation for Safety and Mobility, American Association of State Highway and Transportation Officials, the Insurance Institute for Highway Safety, the travel and tourism industries, National Transportation Safety Board (NTSB), University Transportation Centers (UTCs) and the broader transportation research community.

DOT uses the data to estimate the amount and nature of passenger travel in the U.S., the relationship between socio-economic characteristics and travel patterns, and trends in passenger travel. These data are critical to develop policies related to congestion, mobility, safety, finance, and for forecasting future demand.

Travel behavior data informs on complex and inter-related policies and performance measures. The growing array of travel data needs are a direct result of a growing and changing U.S. population. This creates an even greater need for key measures of travel behavior to support safety, mobility, and congestion strategies as volumes increase, the traveling population ages, the mobility needs of new immigrants require special consideration for alternative modes, and as safety and air quality issues continue to trouble many urban areas. In addition, infrastructure improvements are advocated to safely encourage walking and biking to improve American’s health, new land-use strategies are being implemented to reduce vehicle travel and increase transit use, and new vehicle types are being marketed to reduce energy consumption and greenhouse gas emissions.

OST, FHWA, FTA, NHTSA and BTS use NHTS data to address a number of issues in the Department’s Strategic Plan. Specific applications are outlined below.

Safety

Ensuring the safety of the American public when traveling has been a long standing mission of the Department of Transportation. The NHTS is the only source of data available on the level of use of the transportation system by mode of travel and demographic group. Specifically, NHTS data is used by the Department, Administration, and transportation organizations for:

• Calculating exposure rates by age, gender, and vehicle type to compute risk for crash and fatalities. These data are used to assess impacts of demographic shifts and vehicle technology on the safety of the American public. The risk assessment tool, TrafficSTATS, developed by the AAA Traffic Safety Foundation is one example of this use (http://www.aaafoundation.org).

• Development of educational campaigns that reach target audiences. For example, understanding who is traveling at high accident times allows educational campaigns to target traveling market segments, including details on the age and sex of the driver, the number of people in the vehicle, the purpose of travel, and vehicle characteristics which can impact collision severity, such as vehicle age, type, etc.

• Analysis of the incidence of walk and bike trips, characteristics of those making these trips and the trips themselves, such as time of day, and trip purpose to establish baseline measures of exposure and address high risk areas (e.g. rural roads) and demographic groups (e.g. new immigrants).

• Information on rare modes, such as motorcycle use, to help understand the growth in motorcycle accidents and fatalities in recent years.

• Evaluating new safety initiatives such as Safe Routes to School to understand travel to school to help monitor special programs related to increasing the safety of children walking and biking to school.

Congestion

Reducing the level of congestion in U.S. cities is one of the top priorities of the DOT. The NHTS plays an important role in understanding the travel behavior that contributes to the congestion issue. Travel demand is generated by the choices that people make to carry out their daily activities. The steady increase in travel demand over the past fifty years (especially vehicle travel) has created high levels of congestion in our urban areas. Congestion is no longer only a weekday work commute issue. In fact, approximately half of all travel during peak commute times is for non-work purposes. The NHTS is the only source of information on non-work travel. The NHTS supports policy and planning by DOT, the Administration, and Congress in measuring in the demand side of congestion including:

• Vehicle occupancy during congested times to measure changes in carpool rates,

• Trip purpose distribution for peak and off-peak travel, including non-work,

• Mode share for all trips by time of day and day of week, and

• Trends in time, distance, and speed for work and non-work travel.

• Homeland security issues? E.g., Capacity & congestion of designated evacuation routes

Mobility

Mobility issues are particularly acute for the elderly, new immigrants, and the poor. Issues include access to and use of alternative means of transportation, the range of daily mobility, and the relative cost of transportation for the household. In particular, the NHTS provides data that supports an examination of:

• Mobility of people of color and language minorities, including whether their reduced mobility is due to race/Hispanic origin, income, residential location, or other barriers to access and mobility.

• Women’s travel issues, particularly the travel behavior of working mothers who continue to retain primary responsibility for family and household needs, and elderly women who may be isolated when they give up driving

• Teen travel behavior, especially in the pre-driving age and through the later teens as graduated licensing becomes more common. Teen travel behavior has impacts on safety, household trip generation, and future transportation service needs and demand.

• Transit use is analyzed in terms of the socioeconomic characteristics of users, availability and access to transit, and trip characteristics including wait time, trip purpose, length, travel party size, and time of day.

Economic Issues

Financing options for the highway system and the quantification of the cost of transportation issues such as congestion on the U.S. economy are top issues in the DOT, Congress, and Administration. National data on passenger travel, as collected in the NHTS, informs on key aspects of economic issues related to cost and finance of the surface transportation system. These include:

• Evaluation of highway finance options,

• Measures of efficiency of surface transportation modes, such as travel time data and trends in travel time,

• The impact of user fees based on estimates of the socio-economics of the traveler, the purpose of travel during peak periods, and the other relevant characteristics of peak period travel,

• Characteristics of travel to work, with particular emphasis on the NHTS data serving as a bridge for state and metropolitan planners to use Decennial Census data in their travel models, and

• Data on vehicle ownership, vehicle characteristics and amount of travel are used in the FHWA revenue forecasting model to forecast Highway Trust Fund receipts for use by DOT and the Department of Treasury

Private Vehicle Fleet Characteristics

The NHTS is the only national source of data on the composition of the household vehicle fleet, particularly vehicle type and age, and how it has changed over time. In addition, the Energy Information Agency partners with DOT to append data on fuel efficiency, gas cost (at the household’s location in the month of data collection), and annual fuel use. This data is critical for determining both trends in fuel use and understating the changing types and levels of emissions. Important changes in the character of the vehicle fleet have been tracked using the NHTS data including:

• Increased ownership and use of SUVs and the impacts of that trend on fuel use and vehicle emissions,

• The relative cost of travel and fuel usage by the type of autos owned by the household and the household’s location,

• Increased ownership and use of hybrid vehicles

• Changes in the overall fuel efficiency of the residential vehicle fleet, and

• Changes in the overall age of the residential vehicle fleet and availability of safety features to key demographic groups.

Local Level Planning and Policy

In addition to DOT policy issues and Strategic Plan goals, a key function of NHTS data is in the planning processes of States and MPOs (Metropolitan Planning Organizations). NHTS data is used to supplement, or even substitute for, local data on key variables needed in the policy and planning process. States and MPOs have used NHTS data as inputs into the travel demand forecasting, safety planning, and air quality analyses that are mandated by Congress. Since many large urban areas collect local data, NHTS is most useful to very small MPOs with limited resources and/or to States who are piecing together data from a number of urban areas or require some estimates of rural travel behavior to fill in State data gaps.

3. Extent of automated information collection:

The NHTS obtains information from respondents over the telephone using professionally trained interviewers and a computer-assisted telephone interviewing (CATI) system. This approach allows us to employ the newest computer technology and programming to reduce respondent burden and maximize data quality. First and foremost, CATI systems allows for sophisticated branching and skip patterns, in which the interviewer asks only those questions that are necessary and appropriate to the particular respondent. Another example is the use of look-up data. For example, make and model look-up tables allow interviewers to insert correct vehicle types into the record, and yellow-pages look-up tables allow interviewers to find the correct place name and location without detailed reporting from the respondent. The location data for the respondent’s home, work and/or school is stored and automatically inserted for trips after the first report. Household rostering (the listing of all vehicle and persons in the household) allows a trip report from one household member that includes another (e.g. a husband and wife who go to dinner together) to be automatically inserted into the second interviewee’s record. This reduces burden by not requiring the respondent being interviewed to report a trip that was already reported by a fellow household member.

Of course, data range, consistency, and edit checks are automatically programmed to reduce reporting error, reduce survey length, and maintain the flow of the interview. Data cross checks also help reduce burden by ensuring that the reporting is consistent within each trip, e.g. the vehicle type (“Honda Civic”) automatically appears as the mode of travel throughout the reported trip that starts with the vehicle so the interviewer can simply confirm rather than ask the mode for each trip segment.

Other efforts to automate the information collection and reduce respondent burden involve obtaining data from outside sources rather than asking the respondent. For instance, the 1990 survey asked the respondent whether there was a bus stop near their home and near their work. In the 2001 survey we simply used the geographic locations of bus lines and light rail stops to code the distance from the sampled household to the Bus/Light rail.

In addition to the features provided by the CATI technology, two other approaches using improved technology were considered:

• Offering the option of internet response to the survey, and

• Using Global Positioning System (GPS) technology to collect trip information on an automated basis.

The possibility of internet response is not currently being pursued. We believe the length and amount of detail in the NHTS interview would make it a poor candidate for an internet response format.

Use of GPS technology in collecting household travel data is a state-of-the-art technology that is being used more frequently across the nation. GPS obtains very accurate trip length, travel time, and vehicle speed. Further, GPS data can yield route and facility type information, which is important in examining route choice and shifts in travel due to congestion, tolling, work zones, and accidents. As the technology becomes lighter and smaller, hand-held units are even being used for walk, bike, and transit trips. Unfortunately, the resources are not available to fund a GPS subsample in the 2008 NHTS.

4. Efforts to identify duplication:

The National Household Travel Survey is the only source of information on mode use for all purposes by the American public. The NHTS program works in coordination with several other federal programs to maximize the utility of the information and to identify and eliminate duplication. Key programs that compliment the NHTS are the Highway Performance Monitoring System (HPMS), American Community Survey (ACS), and tourism and traveler surveys such as those collected by the Travel Industry Association (TIA).

For HPMS, FHWA aggregates local vehicle count data from all of the 50 states, the District of Columbia and Puerto Rico. This count data measure the use of the highway system itself and the total volume of travel. To complement these data, the NHTS is required to provide estimates of the proportion of all travel on the roadways that is passenger (that is, generated by individuals in their everyday activities), versus commercial or freight. In addition, the NHTS compliments HPMS data by providing information on the demographics of travelers, the purpose of their trips, and travel party size which cannot be obtained from counts.

The NHTS program coordinates extensively with the Census Bureau, in particular the Journey to

Work data included in the American Community Survey. The Census Bureau has collected information on the work trips since 1960; however, the data is limited to the “typical” work trip including mode and total travel time. NHTS also includes work trip data, but collects information on the characteristics of the actual work trip on the assigned travel day. In addition, the NHTS collects information on all trip purposes. This data are not available through any other source. Overall, work trips represent 17 percent of all trips by all people; even for adults in the workforce the trip to work is only one of four trips made in an average day.

The NHTS program also benchmarks against the American Time Use Survey (ATUS) that is conducted by the Bureau of Labor Statistics. The ATUS does collect some travel information as it provides estimates of the activities people do and the time spent doing them. The level of detail on trip information in the NHTS is not repeated in the ATUS scope.

There are tourist and traveler surveys that provide national data on recreational travel activity; however, these surveys focus on long-distance travel (trips of 100 miles or more). While the NHTS does obtain some long distance information (if a long distance trip was taken on the assigned travel day), the primary focus is on the daily travel of the American public.

Supporting documents submitted compares other national survey efforts in scope and coverage to the NHTS. The chart demonstrates that no other national data source collects the full range of daily travel by all segments of the population on all modes of transportation.

5. Efforts to minimize the burden on small businesses:

Small businesses are not being recruited to participate in this study. No information will be collected from small businesses.

6. Consequences the data not being collected or less frequent data collection:

As NHTS is the only source of national data on the travel of the American public by all modes and for all purposes, the Administration, Congress, and the DOT would be missing essential information regarding key transportation indicators. These include mode share, travel demand, trip purpose distribution, and exposure levels that feed directly into transportation and safety planning, program evaluation, highway finance, performance measurement, and policy development. Without the next survey in the series, the transportation community will have no information on:

• Changes in the purpose and type of travel related to increases in fuel costs. The Energy Information Agency appends current fuel data onto the NHTS, but changes in behavior related to the price of fuel require new travel information. In addition, the vehicle fleet is changing, and tracking the penetration and use of alternate fuel vehicles is important in revenue forecasting for the Department,

• Vehicle miles of travel by drivers by age, sex, ethnicity, and time of day. This has been used in applications from safety measures and program evaluation to outreach targeting to evaluating the occurrence of racial profiling,

• Impact of baby-boomers retirement and working past traditional retirement age. Important demographic changes are occurring in the users of the transportation system, effecting congestion, trip purpose and time of day of travel, and other information important to policy analysis,

• Measures of peak spreading, and increases in midday and weekend travel. For many areas around the country, vehicle starts on Saturday afternoon are higher than any peak period during the weekday (expect Friday afternoon),

• Travel by special populations, such as the disabled, new immigrants, poor, and people without cars. This data is vital for evacuation planning, mobility, and safety,

• Effects of graduated licensing programs on teen driving. As more and more states use graduated licensing, the effect on vehicle occupancy, age, purpose, and time of day of travel are important to track, and

• Updates to the default air-quality and trip generation parameters used by local planners. These data feed local models that forecast travel demand for major investment studies, congestion pricing, new transit starts, and other local transportation improvements.

As a data driven agency, FHWA needs to continue its leadership in collecting and disseminating information that support sound planning and policies at all levels of government. FHWA’s continued leadership at the Federal, State, and local level will have an enormous impact on the safety, reliability, and accessibility of our system in the future. The NHTS provides data that informs DOT and FHWA on travel behavior that impacts our decisions and programs related to DOT’s strategic goals. The NHTS is a critical data program. For the upcoming reauthorization, the NHTS will be an important resource in confirming national strategies and priorities.

7. Special circumstances:

There are no special circumstances.

8. Compliance with 5 CFR 1320.8:

The Federal Register Notice was released on May 11^th, 2007. Three (3) comments were submitted to Docket No. FHWA-2007-28076 in response to the Federal Register Notice and Request for Comments published at page 26862. All comments were in support of the NHTS program. Two were from state departments of transportation (Ohio DOT and Florida DOT). The third comment was from The Brookings Institute which stressed the importance of NHTS data to the Department and to metropolitan areas. In addition, the Brooking Institute stressed the need for greater and more regular funding levels for the NHTS program. The 30-Day Federal Register notice was posted on July 30, 2007.

9. Payments or gifts to respondents:

In both the pretest and the full survey, a small monetary pre-incentive will be sent with the first contact materials and a second small incentive will be mailed with the travel diaries. The primary reason why small monetary incentives are planned is that they have been shown (both in the literature and in our previous survey experience) to increase response rates. Planned incentive levels for the 2008 NHTS are a $5 incentive sent out with the advance mailing and a $2 per diary incentive mailed to the household following the recruitment interview. This latter person-based incentive has been shown to increase household response rates in the second (trip retrieval) stage of the study. A controlled incentive experiment was conducted during the 2001 NHTS pilot survey to determine the impact of various incentive levels on response rates. This is discussed in section B of this submission.

The pretest will consist of a full “dress rehearsal” test of the questionnaire, systems, interviewer training, and survey protocols to be used for main data collection in the 2008 NHTS. The pretest will be conducted with a sample of 200 households with 50 percent in a rural area and the remaining 50 percent in an urban area to assure a good distribution of urban and rural household characteristics and transportation options. We believe 200 completes will be sufficient to test the systems, the focus of this pretest, as there are minimal design changes from the 2001 NHTS. Actual survey conditions in the pretest will be simulated as closely as possible, verifying that the CATI systems are working properly, modifications to the questionnaire flow well, and all mailing systems are operational. The pretest will also exercise the data preparation editing protocols and data and file management systems.

10. Assurance of confidentiality:

Household information will only be maintained during data collection in order to contact household via telephone to conduct the survey and mail out field materials (including travel diaries) to household members. Household information for these purposes includes address and phone numbers. Households are not required to provide the names of household members. To protect the identity of the respondents, the final database will not contain names, addresses, telephone numbers, or other direct identifiers. Neither will the data files contain variables that could be used to match records to an external file containing names and addresses.

Confidentiality procedures will also be applied rigidly to all electronic files. Password systems will be maintained to ensure that only authorized staff members can access the files. Furthermore, physical access to the computer equipment will be restricted to authorized systems operations personnel.

The contractor will apprise project staff members of legislation and guidelines concerning protection of human subjects and their right to privacy. All contractor personnel associated with the survey, including interviewers, interviewer supervisors, and professional staff, will be required to sign a statement pledging to maintain the confidentiality of all survey data.

Informed consent procedures will be implemented for the NHTS. The contractor will inform each survey respondent of the following: the enabling legislation for the study, the principal purposes for which the information is needed, the routine uses that will be made of the data collected, that their participation is voluntary and there is no penalty for non-participation. The respondent will also be told that their responses will be held in the strictest confidence and that reports from the survey data will be summaries that do not allow individuals from being identified. A statement to this effect will be included in the introduction to the NHTS questionnaire.

10. Justification for collection of sensitive information:

Every effort has been made to reduce the number of sensitive questions in the 2008 NHTS questionnaire. There are, however, several important questions that could be considered sensitive by some respondents.

An income question is included along with other questions designed to identify socioeconomic characteristics that are vital to the travel analyses. It is necessary to collect income data because there is a direct correlation between travel behavior and the financial resources available to the household. The link between household income and the amount of travel as well as the types of trips made is critical in analyzing current travel or projecting travel in the future. Travel forecasting models most often use household size and income as prime determinants of projected travel. Total combined family income will be asked of one household respondent for each household; individual family members will not be asked for their personal income. If any non-family members reside in the household, they will be asked for their income individually because it is unlikely that the household respondent will have such information.

Questions on immigrant status were introduced in the 2001 survey. The questions have tested well and been highly useful in policy and program analyses regarding immigrant travel behavior and demand projections. This was added because 1) so much of the projected growth of the U.S. population over the next several decades will result from immigration, and 2) immigrants, particularly recent immigrants, face unique travel and mobility challenges. We recognize the sensitivity of asking immigrant status and will continue to closely monitor respondent sensitivity to this topic.

Verification of home and workplace location is requested by respondents in the NHTS. Home addresses will already be provided for persons with listed telephone numbers. If this information is refused the names of the streets at the nearest intersection will be requested. This information is not included in the public use data file and only available to users within the Department of Transportation and academic research community under a strict confidentiality agreement. This data is needed to verify distance to work information for congestion management policy and to correctly code transit availability as a mode option at work and home.

10. Estimate of burden hours for information requested:

The respondent burden for the NHTS will result from the time spent hearing the explanations and questions and responding to them during the telephone screening, interviewing, and verification. The NHTS is a two-stage study. In the first stage, households are contacted via computer assisted telephone interviewing (CATI) to collect basic information about the household and its vehicles. During this initial contact (household interview), households are recruited to participate in the NHTS and assigned a specific travel day. The household is asked to record details about each trip taken on that day.

Minimal recordkeeping is required by most respondents. The recordkeeping consists of maintaining a simple travel diary for a 24-hour period. The diary is a straightforward form that asks the respondent to record six items for each trip: where they went (e.g. home, work, other), why they went (work, school, shop, etc), the time the trip began and ended, the means of transportation, and who traveled with you. Our experience shows that use of the travel diary improves recall of specific trips, particularly incidental trips.

In stage 2, the trip information is obtained from each household member (trip level interview) via CATI. The interview asks details about each trip while the diary serves as a memory jogger.

For the 2008 NHTS, the estimated average burden per household is 49 minutes. We are calculating the reporting burden as follows:

49 minutes total burden per household composed of:

Household Interview – conducted with one household member: 13 minutes

Record Keeping – 2.6 persons per household @ 4 minutes each: 10 minutes

Trip Level Interview – 2.6 persons per household @ 10 minutes each: 26 minutes

The total number of households included in the pretest is 200. The total number of households included in the main study is 25,000. Therefore, the total reporting burden (25,000 households @ 49 minutes per household) is 20,417 hours. In addition, 200 pretest households add 163hours of burden. The combined total of 20,580 total burden hours at $11.91 per hour sums to $245,108 in annualized cost to respondents. This represents a reduction in burden level from 52 minutes per household in the 2001 NHTS. The causes for this reduction are addressed in item 15 of this Supporting Statement.

13. Estimate of total annual costs to respondents:

There are no costs to the participants beyond the hour burden.

14. Estimate of cost to the Federal government:

The total cost of this survey to the Federal Government is $7.2 million. The detailed cost breakdown is included in Table 1.

Table 1: Total NHTS Program Costs

Major Tasks	Cost
Program Management (One FTE)	$325,000
Design and Conduct	$4,500,000
Database Development	$450,000
In-House Analysis, Quality Assurance, Reporting, and User Support (contractor support)	$1,200,000
Statistical Analyses, evaluation, and on-line data analysis tool (contractor)	$725,000
Total Cost	$7,200,000

15. Explanation of program changes or adjustments:

The burden was reduced from the 2001 survey by editing the questionnaire to only the most critical data elements and eliminating the reporting of odometer readings twice over a two-month period. An adjustment for burden was also made due to two methods changes. In 2001, the NHTS collected trip information for children under the age of five. Based on an analysis of the number of trips taken by children under five without a household member, we have determined that we no longer need to collect data on children under the age of five. In addition, a separate module for the collection of long distance trip information has been removed from the 2008 NHTS.

16. Publication of results of data collection:

Congress requires the USDOT to report the state and performance of the transportation system every two years in the Conditions and Performance Report. The NHTS is used in this report. The NHTS is also used extensively in the existing National Surface Transportation Policy and Revenue Study Commission with regards to forecasted travel demand by geographic and demographic groupings. In addition, the NHTS data has informed on several policy and revenue areas through white papers on topics such as trends and forecasts in telecommuting, work and non-work travel, new immigrant travel, and older driver safety.

Other reports are compiled for the Department of Transportation, state and local agencies, and the transportation research community, including Summary of Travel Trends and Our Nation’s Travel. These reports provide key indicators of travel demand across trip, person, household, and vehicle characteristics. In addition, bi-monthly briefs on current transportation policy issues are sent to USDOT and outside parties. All reports and documentation from the 2001 NHTS and previous surveys can be found on our study website at http://nhts.ornl.gov

17. Approval for not displaying the expiration date of OMB approval:

Not applicable.

18. Exceptions to certification statement:

None.

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