Improving Transportation Statistics

Improving Transportation Statistics

The Bureau of Transportation Statistics (BTS) program offices have taken steps to close data gaps or improve the ways in which they collect, compile, analyze, and publish data.

Freight Data

The North American TransBorder Freight Data Program provides users with data and information on shipments transported between the United States and Canada, and between the United States and Mexico. These data are an extract of the official foreign trade statistics collected by the U.S. Bureau of the Census.  The program maintains the data and publishes subsets of the data electronically.

The North American TransBorder Freight Data provide U.S.-Canada and U.S.-Mexico merchandise trade data by commodity type, mode of transportation (rail, truck, pipeline, water, air, and other), and geographic detail for U.S. exports to and imports from Canada and Mexico. Since April 1993, the program has made the data available via the Internet at http://www.bts.gov/programs/international/transborder/.

BTS made two major changes to the TransBorder Freight Data Program in 2007. First, beginning in January 2007, the program added a new combination of U.S. port entry/exit and commodity data (at the two-digit Harmonized Tariff System level), which provides users with details on North American freight transportation not previously available.

Also in 2007, in response to customer feedback and advances in technology, the TransBorder Freight data interface was significantly improved. BTS developed a powerful online data access tool, which now provides fast queries and accurate analytical results to the user.

The new TransBorder query system produces:

  • Detailed Statistics - that provides users with the ability to make queries of the following data elements:
    • U.S. State
    • Trading partner
    • Customs port
    • Mode of transportation
    • Value or weight
    • Imports, exports, or total trade
    • Commodity (at the two digit Harmonized Tariff System level)
    • Year
    • Month
  • Fast Facts - provides users with fast and simple annual and monthly trade and transportation facts such as the top 10 ports, top U.S. states and top commodities in terms of trade value or weight for different modes of transportation.

The Commodity Flow Survey (CFS) represents the primary source of national and state-level data on domestic freight shipments by U.S. establishments in mining, manufacturing, wholesale, auxiliaries, and selected retail industries. CFS data provide the type, origin and destination, value, weight, mode of transport, distance shipped, and ton-miles of commodities shipped. Conducted every 5 years as part of the Economic Census, the CFS is a shipper-based survey. It provides a modal picture of national freight flows and represents the only publicly available source of commodity flow data for the highway mode. In addition, the CFS also provides one of the most comprehensive data series on the shipment of hazardous materials and exports.

During the spring of 2008, BTS, in partnership with the U.S. Census Bureau, completed data collection for the 2007 CFS. BTS and the Census Bureau previously conducted the CFS in 1993, 1997, and 2002. In response to data users and stakeholders' consultations and an extensive research effort, BTS and the Census Bureau implemented significant improvements in the survey design, collection instruments, and data products. Examples include an expansion of coverage in both geography and industry, addition of items on intermodal freight shipments and third-party logistics usage, and overall improvement in the data content, products, and means of dissemination. Processing of the 2007 CFS data continued through 2008 with BTS releasing the preliminary estimates from the survey in December 2008, to be followed by the release of final data products in December 2009. All 2007 CFS data products, as well as those from previous surveys, are available via the Internet at http://www.bts.gov/publications/commodity_flow_survey/ and via the U.S. Census Bureau's American Fact Finder-http://factfinder.census.gov/.

The Federal Highway Administration (FHWA) is conducting the planning and design work for Version 3 of the Freight Analysis Framework (FAF3). The FHWA will base the FAF3, in part, on data from the 2007 CFS. Furthermore, FAF3 integrates data from a variety of sources to estimate freight transportation activity among states, regions, and major international gateways. Based on the 2002 CFS, the current FAF provides estimates for 2002, quinquennial forecasts from 2010 through 2035, and annual provisional estimates (2007 released in April 2008). A searchable web-based database is also under development that, when completed, will provide improved access to the FAF data. All of the FAF data products are available via the Internet at http://www.ops.fhwa.dot.gov/freight/freight_analysis/faf.

This year the Committee on the Marine Transportation System (CMTS) launched the Marine Transportation System (MTS) Data Inventory, http://marapps.dot.gov/mts/, which is a web-based product of the CMTS Data Collection and Information Management Integrated Action Team (IAT). The MTS Data Inventory includes marine transportation-related data and information that federal agencies either produce or use. The Maritime Administration leads the IAT, whose membership from within the U.S. DOT includes the Maritime Administration, Saint Lawrence Seaway Development Corp., Federal Highway Administration, Bureau of Transportation Statistics, Federal Railroad Administration, and Pipeline and Hazardous Materials Safety Administration. In addition, the team includes federal agencies from the U.S. Departments of Defense, Homeland Security, Commerce, Energy, Labor, Interior, Agriculture, State as well as the Environmental Protection Agency, and the Federal Maritime Commission.

Passenger Data

During 2008, BTS issued a final rule improving the data collected to document the on-time performance of airlines. The new rule took effect on Oct. 1, 2008. BTS added provisions to include more details on tarmac delays for cancelled and diverted flights. When an airline diverts a flight, it will now report the name of the diversion airport and all ground times, incoming and outgoing, at the diversion airport, even if the airline cancels a flight at the diversion airport.

The final rule also requires that an airline record all ground time as a delay when a flight is cancelled after leaving the gate and then returning. In the past, BTS only collected the number of airline flight cancellations from the airlines. BTS did not collect the tarmac delays—the time spent away from the gate. Now, the rule establishes a uniform practice for recording when a flight leaves the gate, returns to the gate, and then departs a second time. Delay statistics now reflect both departures. More specifically, BTS records the second departure as the actual departure time when compared to the scheduled departure time and records the total taxi-out times.

BTS has continued developing an e-filing data collection process. BTS now collects the majority of T-100 traffic data for Alaskan carriers using this new method.  E-filing offers secure data transfer with little or no additional work on the part of the airlines. Upon receipt at BTS, it also reduces the manual processing of the data.  Several large U.S. carriers have voluntarily begun test submissions involving their large data transfers.  BTS envisions that most, if not all, airlines will file their T-100 traffic data using this more secure and efficient way by the end of 2009.    

The Passenger Intermodal Connectivity Database offers data on the scheduled public transportation modes serving individual passenger transportation terminals in the United States. BTS developed this database to serve as a baseline measurement of the intermodal connections that are available in the U.S. passenger transportation system. Since the passage of the Intermodal Surface Transportation Act (ISTEA) in 1991, all U.S. DOT authorizing legislation has encouraged the development of intermodal links. Therefore, establishment of a baseline measurement for passenger intermodal connectivity will provide one way to measure U.S. progress.

BTS compiled the data in phases, by mode, for the Passenger Intermodal Connectivity Database. The initial phase of the Passenger Intermodal Connectivity Database, which includes data on 1,220 passenger terminals—547 intercity rail stations and 673 scheduled service airline airports—became available in 2007. Late in 2008, BTS added data covering 296 ferry terminals with scheduled passenger service. Also during 2008, data collection began on commuter rail stations, which will be the next mode added to the database during 20091. Data for heavy rail (subway), light rail (streetcar), and intercity bus stations will complete the database in future years.

BTS has been collecting the data on modes serving each terminal from numerous public sources including databases at the U.S. DOT, published brochures and timetables from carriers and transit agencies, and information from a range of transportation websites. These databases are available via the Internet for downloading as spreadsheets at http://www.transtats.bts.gov/. BTS has issued Special Reports using this data examining the degree of connectivity at intercity rail stations, airports, and ferry terminals. These reports are available at http://www.bts.gov/publications/bts_special_report/.

The Passenger Intermodal Connectivity Database includes the following categories of data for each terminal record:

  • terminal name, address, zip code, and metropolitan area status;
  • latitude and longitude;
  • number of modes serving;
  • status of service for ferry (intercity and transit), bus (intercity, transit, code share/supplemental), rail (intercity, commuter, heavy rail, and light rail), and air modes;
  • terminal website; and
  • data sources.

In accordance with Section 1801(e) of the Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU), BTS established and will maintain a national ferry database containing information on ferry routes, vessels, passengers and vehicles carried, funding sources, and other operational details.

The National Census of Ferry Operators (NCFO) database is available via the Internet at http://www.bts.gov. The NCFO database is a collection of summary tables that provide operational ferry data from a nationwide census of ferry operators conducted in 2000 and 2006. The 2008 survey is currently underway. The NCFO database contains data from other sources of ferry data such as the U.S. Coast Guard and the U.S. Army Corps of Engineers. BTS collects numerous detailed data elements describing the services that ferry operators provide as part of this effort. The NCFO utilizes a relational database throughout the data collection and processing that provides for the reporting of the information at various levels, such as by operator, route segment, terminal, or vessel.

The database of existing ferry operations includes the United States and its possessions, encompassing the 50 states, Puerto Rico, the U.S. Virgin Islands, and the Commonwealth of the Northern Mariana Islands. In addition to ferry operators providing domestic service within the United States and among its possessions, foreign operators providing international services to or from at least one U.S. terminal are also included.

The 2008 NCFO includes some additional response categories for existing items on vessel characteristics, route characteristics, and terminal characteristics. For example, BTS asks operators whether a vessel is currently in service, if it is passenger only, which vessel sails a trip segment, and how many trips the vessel makes in one day. In addition, BTS asks operators to select the proximity to other transit modes and to provide information on other businesses operating at their terminals. This additional information will enhance the ability to perform multiple imputation of missing passenger-boarding data and will provide more detail on interconnectivity with other transit modes. In early 2009, BTS plans to release a summary report based on a 2008 website survey. A summary report of the 2006 survey findings is available at: http://www.bts.gov/publications/bts_special_report/.

BTS will conduct the next the NCFO in 2010. BTS is working with the Maritime Security Program of the U.S. Department of Homeland Security to include questions on security screening procedures used by terminal and ferry operators.

The Federal Highway Administration (FHWA), Office of Highway Policy and Information, is conducting the National Household Travel Survey (NHTS) in 2008. It is the foremost official national source of information on travel by the American public. Since 1969, the NHTS has provided an inventory on daily travel by all modes, purposes, distances, travel times, occupancy, and a host of other travel data. NHTS provides an important contribution to understanding transportation issues of congestion, safety, highway finance, economic impacts, air quality, and fuel use. The study also contributes to the understanding of social travel trends that affect measurements for transportation modeling, policy, and program evaluation. The 2008 NHTS includes additional information on the flexibility of work schedules, telecommuting, home deliveries from Internet shopping, hybrid and alternative fuel vehicles, commercial licensed vehicles, interstate and toll use, disabilities affecting mobility, and schoolchildren travel. With 40 years of data, the NHTS adds a wealth of information to help understand the complex nature of travel behavior.

The 2008 NHTS is the largest travel survey in the world. The study encompasses a national and add-on sample, which combined will yield data from 150,000 households. The national component covers all 50 states plus the District of Columbia. It employs a dual frame sample design that includes both landline and cellular phones. The frames generate 25,000 households for landline and 1,250 for cell-only households. The second component—the add-on program—represents a collection of state and metropolitan supplemental samples. Twenty areas are participating in the 2008 add-on program, resulting in data from an additional 125,000 households.

The combined sample of over 150,000 households will integrate and optimize the national survey with the add-on sample.

Below is a list of the 20 2008 NHTS add-on program participants:

1. California DOT 11. Omaha, NE
2. Chittenden County, VT 12. Piedmont Regional, NC
3. Florida DOT 13. Tucson, AZ
4. Georgia DOT 14. South Carolina DOT
5. Indiana DOT 15. South Dakota DOT
6. Iowa DOT 16. Tennessee DOT
7. Cedar Rapids Regional, IA 17. Texas DOT
8. Phoenix, AZ 18. Vermont DOT
9. New York State DOT 19. Virginia DOT
10. North Carolina DOT 20. Wisconsin DOT

The NHTS launched its data collection efforts in March of 2008. The data collection will continue for over a full year until the first week of May 2009. The NHTS provides a full year of travel data to allow for day-of-week and month-of-year analyses of travel demand. In the fall of 2009, FHWA expects to make a microdata file publicly available for travel behavior modelers, policy analysts, and scholars.

Geospatial Information

The RITA/BTS Geospatial Information Program is the lead program for geospatial activities within the U.S. DOT. To emphasize this geospatial role, the U.S. DOT appointed the BTS Program Manager as the first Geospatial Information Officer. The Program is the U.S. DOT lead for National Spatial Data Infrastructure (NSDI). NSDI activities include representing DOT in the Federal Geographic Data Committee (FGDC) and OMB e-Gov initiatives, such as the Geospatial Line of Business, as well as leading the development of transportation data content standards for the Geospatial One-stop.

The Geospatial Information Program has worked with U.S. DOT partners to fill geospatial data gaps. Over the past 5 years, the Program and its partners have developed geospatial data for fixed guideway transit lines and stations, multimodal transfer facilities, Metropolitan Planning Organization boundaries, Environmental Protection Agency nonattainment area boundaries, road bridges from the National Bridge Inventory, highway weigh-in-motion stations, highway automated traffic recorder stations, highway hazardous materials routes, ferry routes, and alternative fueling stations. In 2009, the BTS Program will collaborate with the Federal Railroad Administration to develop a geospatial database of rail bridges.

The Geospatial Information Program annually produces the National Transportation Atlas Databases (NTAD). NTAD is a set of nationwide geospatial databases of transportation facilities, transportation networks, and associated infrastructure. These datasets include geospatial information for transportation modal networks and intermodal terminals, as well as the related attribute information for these features. Each database, as prescribed by the FGDC, provides metadata documentation. These data support research, analysis, and decisionmaking across all modes of transportation. They are most useful at the national level, but have major applications at regional, state, and local levels throughout the transportation community. U.S. DOT partners and other federal government agencies provide the data used to compile NTAD. Congress originally mandated the Geospatial Information Program to produce NTAD in the Intermodal Surface Transportation Efficiency Act of 1991. The mandate has continued in each subsequent transportation authorization.

The Geospatial Information Program develops GIS applications to assist transportation analysts in performing complex geospatial analyses. For example, the GeoMiler application helps estimate freight travel by computing mileages along likely routes for the nearly 5 million freight shipments in the 2007 Commodity Flow Survey (CFS), the nation’s largest survey of freight movement. The CFS uses these computations in estimating modal ton-miles of freight—a key measure for understanding the use and performance of our nation’s freight transportation system. The Geospatial Information Program developed GeoMiler using current GIS technology to assign routes and calculate mileage from the true origin to the true destination of each shipment reported in the CFS, even when more than one mode is used. While developed for use in processing the CFS, multimodal freight movement at all geographic levels may use the tool’s integrated core GIS technology and its modeling approach.

Economic Data

The publication of the Transportation Services Index (TSI) in March 2004 marked the entry of the RITA/BTS into the company of federal statistical agencies that produce a monthly U.S. economic indicator. The index consists of three measures:

  • Freight transportation service,
  • Passenger transportation service, and a
  • Combined total of both freight and passenger services.

Currently, the Freight index consists of data from for-hire trucking, rail, inland waterways, pipelines, and airfreight. The Passenger index consists of data from air, local transit, and intercity rail. In addition, as part of ongoing research, BTS is exploring other modal data series to incorporate into the TSI. More specifically, BTS has been evaluating the addition of Federal Highway Administration’s vehicle miles of travel (VMT). Based on the outcome of this research, BTS will decide whether to incorporate highway VMT with the passenger data to create a more comprehensive passenger index. BTS used economic and statistical techniques to present the output of the different transportation modes in comparable terms, while adjusting to correct for the seasonal nature of transportation. Using 2000 as a base year with an index value of 100, the overall TSI has ranged from a value of 66 at the beginning of 1990 to approximately 112 at the end of 2007, reflecting an increase of nearly 70 percent over 17 years.

BTS has undertaken research on how the pattern of change in the TSI compared with the growth of Gross Domestic Product (GDP) and with other measures of the business activity. The Passenger TSI has grown over time, despite a sharp drop at the time of the terrorist acts of Sept. 11, 2001, and its growth tends to coincide with growth in the Gross Domestic Product (GDP). The Freight TSI has grown over time as well, though it has grown more slowly than GDP. It tends to move ahead of GDP – that is, it begins to increase its rate of growth before GDP does, and it tends to decrease before GDP declines or slows down. In 2008, BTS made no annual revisions to the TSI, which follows the annual revisions in 2007 due to resource constraints. However, BTS plans to complete an annual revision in 2009.

Transportation Research Board

RITA, through its program offices, participates in multiple activities of the National Academy of Sciences’ (NAS’) Transportation Research Board (TRB). The TRB is a division of the National Research Council that promotes innovation and progress in transportation through research.

Through an agreement with the NAS, RITA utilizes the TRB to support and carryout administrative and management activities of the National Cooperative Freight Research Program (NCFRP). In 2005, Congress established the NCFRP in the Safe, Accountable, Flexible, Efficient Transpor tation Equity Act: A Legacy for Users (SAFETEA-LU). The NCFRP carries out applied research with the objective of improving the efficiency, reliability, safety, and security of the nation’s freight system. Since the program began, BTS and other RITA staff have participated in the identification and selection of 18 NCFRP projects amounting to almost 6 million in funding.

During the past year, BTS staff participated in many TRB committee activities involving areas associated with freight and travel data, hazardous materials, maritime activities, survey methodology, and international and state transportation topics. The Research and Innovative Technology Administration’s University Transportation Center sponsored a TRB workshop on Research Issues in Freight Transportation – Congestion and System Performance in fiscal year 2008. Other TRB workshops and conferences attended and/or sponsored by RITA involved topics such as Data for Goods Movement Impacts on Air Quality Workshop and North American Freight Flows Conference: Understanding Changes and Improving Data Sources. These workshops and conferences are in addition to staff involvement and attendance at the TRB Annual and midyear meetings, which involve standing committee meetings as well as workshops and presentations.

1 In some locations, commuter rail systems use the same right-of-way and stations as the intercity rail system (Amtrak and the Alaska Railroad). As a result, some stations served by commuter rail are already included in the database since intercity rail serves them.