In this edition of the Transportation Statistics Annual Report, the Bureau of Transportation Statistics (BTS) focuses on transportation indicators related to 15 specific topics (chapter 2) and on the state of transportation statistics (chapter 3).
Chapter 2 contains transportation data and information
on the following topics:1
1. productivity in the transportation sector,
2. traffic flows,
3. travel times,
4. vehicle weights,
5. variables influencing traveling behavior,
6. travel costs of intracity commuting and intercity trips,
7. availability of mass transit and number of passengers served,
8. frequency of vehicle and transportation facility repairs and other interruptions of transportation service,
10. collateral damage to the human and natural environment,
11. condition of the transportation system,
12. transportation-related variables that influence global competitiveness,
13. transportation and economic growth,
14. government transportation finance, and
15. transportation energy.
Two differing indicators of economic productivity exist: multifactor and labor productivity. Labor productivity relates output to labor input, while multifactor productivity relates changes in output to changes in a complete set of inputs, including capital, labor, energy, materials, and services. Multifactor productivity is, thus, a more comprehensive indicator. However, air and rail are the only components of the transportation sector for which multifactor productivity estimates are currently available (from the Bureau of Labor Statistics—BLS); BTS is developing them for all modes using BLS methodologies.
Labor productivity in the for-hire transportation services and petroleum pipeline industries increased 16 percent between 1991 and 2001, a slower rate than the entire business sector, which rose 23 percent. Among transportation modes, rail increased the most, by 64 percent from 1991 to 2001. Despite a decline of 6 percent between 2000 and 2001, air transportation labor productivity grew 18 percent over the entire period.
Multifactor productivity of all business sectors combined increased 10 percent between 1991 and 2001, while multifactor productivity in air transportation increased 16 percent (figure A).
Tracking the volume and geographic flow of traffic on America’s roads, rails, and waterways and at airports helps to ensure that transportation infrastructure is properly maintained and has adequate capacity to meet the demand. Data on traffic flows also help to evaluate congestion trends by mode or a combination of modes and the potential for shifts in traffic within the route structure of a particular mode and from one mode to another. Aggregate traffic flow data, used to evaluate trends over time, can be helpful in measuring transportation-related safety and environmental trends.
Passenger and freight flows are measured in a variety of ways. Vehicle-miles of travel (vmt) for both passenger and freight are calculated by multiplying the number of vehicles by miles of travel. Passenger travel can also be measured by estimating the number of miles traveled per person for each mode (box 2). This method takes into account not only the distance traveled by a vehicle but also the number of people in the vehicle. In addition to vmt, freight flows are measured in ton-miles—the movement of one ton of cargo the distance of one mile. Each of these measurements allows for comparisons across modes and between passenger and freight traffic, although these comparisons are affected by data-collection methods and definitions.
Passenger-miles of travel (pmt) in the United States totaled an estimated 4.8 trillion in 2001, or about 17,000 miles for every man, woman, and child. Over the decade 1991 to 2001, pmt increased 24 percent. Over 85 percent of pmt in 2001 was in personal vehicles (passenger cars and light trucks, which include sport utility vehicles, pickup trucks, and minivans). Air carriers accounted for another 10 percent of pmt (figure B).
As with pmt, BTS employs differing methodologies to generate freight ton-miles. When individual, modal ton-mile data are combined, freight transportation generated 4.3 trillion domestic ton-miles in 2001, 20 percent more than in 1991 (figure C). Based on preliminary data from the 2002 Commodity Flow Survey (CFS) combined with supplemental estimates, freight activity totaled 4.5 trillion ton-miles, an increase of 24 percent between 1993 and 2002.2 There were 15.8 billion tons of commodities shipped in 2002 (up 18 percent since 1993) at a value of $10.5 trillion (in chained 2000 dollars),3 up 45 percent since 1993.
Highway passenger vmt dominates total highway vmt and amounted to 2,641.2 billion (2.6 trillion) in 2002, up 26 percent since 1992. Meanwhile, domestic service air carrier (aircraft) vmt rose 41 percent to total 5.6 billion in 2002. Freight highway vmt totaled 214.5 billion in 2002, a growth of 40 percent since 1992.
In addition to studying freight and passenger volumes, it is also important to track changes in the geographic and modal distribution of freight and passenger travel in order to anticipate and alleviate areas of high congestion and for other purposes. Truck, rail, and waterborne freight flow maps, using tools such as GeoFreight,4 help planners pinpoint potential problem areas in the transportation system.
How long it takes people and goods to get from their starting point to their final destination is a key measure of transportation system performance. Many current measures of travel time trends tend to focus on delay, congestion, and whether or not scheduled trips arrive on time. While delay and congestion measures are important, they are by no means the only consideration in evaluating these trends.
New research at BTS on an Air Travel Time Variability Index aims to improve the measurement of air travel time and reliability. In preliminary results, the index rose by 4 percent per year between 1990 and 2000 and then fell by 12 percent per year between 2000 and 2002, indicating that the actual travel time for a typical flight became more uncertain and took longer, on average, between 1990 and 2000 and then improved starting in 2001 (figure D).
The data supporting the new Air Travel Time Index are collected by BTS from air carriers with at least 1 percent of total domestic passenger revenues. These Air Service Quality Performance data5 also show that nearly 82 percent of domestic air flights arrived on time in 2003, compared with 79 percent in 1995. On average, 37 percent of delays between July 2003 and January 2004 occurred because of circumstances within an airline’s control, such as maintenance or crew problems, while 40 percent happened because a previous flight arrived late. Security delays caused less than 1 percent of delays, on average, and extreme weather, 7 percent.
For those using personal vehicles, highway travel times increased in 72 of 75 urban areas (95 percent) between 1991 and 2001. In 2001, it took 39 percent longer, on average, to make a peak period trip in urban areas compared with the time it would take if traffic were flowing freely. More than two of five adults in the United States reported in 2002 that traffic congestion was a problem in their community, according to the BTS Omnibus Household Surveys.
Seventy-four percent of Amtrak trains arrived at their final destination on time in 2003, compared with 72 percent in 1993. During this period, short-distance trains—those with runs of less than 400 miles—have consistently registered better on-time performance than long-distance trains— those of 400 miles or more.
Vehicle traffic affects the condition and longevity of infrastructure. Traffic on a given highway segment can be measured by average weights and numbers of vehicles. A way to assess the resultant highway pavement stress is by estimating vehicle loadings6 on the nation’s highways. Aircraft landing weights can affect airport pavement, as can the weight of rail equipment on rail tracks. For maritime infrastructure, especially ports, vessel size—often expressed in deadweight tons (dwt), which is a measure of cargo capacity rather than weight—can be of concern. As larger waterborne vessels are added to the worldwide merchant marine fleet, U.S. ports may have to expand to accommodate larger ships or decide to specialize in handling cargoes that are not affected by changes in vessel size.
The number of trucks in the U.S. truck fleet grew 23 percent between 1992 and 1997.7 In the heavy category (over 26,000 pounds), the number of trucks grew 37 percent during the period, while medium trucks (between 6,001 and 19,500 pounds) increased 14 percent. Light trucks, which include sport utility vehicles (SUVs), minivans, vans, and pickup trucks, represented 85 percent of the truck fleet in 1997. The number of light trucks increased by 24 percent between 1992 and 1997; however, the strongest growth occurred among the light truck subcategories of SUVs (93 percent) and minivans (61 percent).
Large combination trucks8 made up only 6 percent of traffic volume on urban Interstate highways in 2002, but accounted for 77 percent of the loadings on these highways. In rural areas, they represented 18 percent of traffic and 89 percent of Interstate loadings in 2002. Between 1992 and 2002, large combination truck traffic volume grew from 16 percent to 18 percent on rural roads, while decreasing from 7 percent to 6 percent on urban Interstate highways.
The average capacity of containerships calling at U.S. ports increased 16 percent to 42,158 dwt per call between 1998 and 2002.9 Meanwhile, the average capacity of all types of vessels calling at U.S. ports grew 5 percent, to 47,625 dwt per call in 2002 (figure E).
The average weight of each freight railcar remained fairly constant—ranging from 62 to 67 tons per carload—between 1992 and 2002. However, this relatively steady average weight of a loaded railcar masks countervailing trends among selected freight commodities. For instance, the average weight of a carload of coal was 111 tons in 2002, up from 99 tons in 1992. Meanwhile, miscellaneous mixed shipment carloads were 14 percent lighter in 2002 than they were in 1992.
Travel patterns across the nation are the result of literally millions of different decisions by individuals and businesses. Travel behavior both shapes and is shaped by available transportation options. Hence, understanding the variables that influence travel behavior are important in evaluating transportation needs and making appropriate decisions about changes in the system.
Results from the 2001 National Household Travel Survey (NHTS),10 sponsored by BTS and the Federal Highway Administration, show that the daily non-occupational travel of all people in the United States totaled about 4 trillion miles, an average of 14,500 miles per person per year. On a daily basis, each person traveled an average of 40 miles, 88 percent of it in a personal vehicle.11 Overall, people took 411 billion daily one-way trips in 2001, an average of 1,500 trips per person annually or about 4 trips per day. The largest number of daily trips (45 percent) were to shop, to visit doctors and dentists, and for other family and personal business. Commuting—trips made to and from work—accounted for 15 percent of all personal trips in 2001. The average length of these trips was 12 miles.
On average, each person made 9 roundtrip long-distance trips of at least 50 miles in 2001 for a total of 2.6 billion trips covering 1.4 trillion miles. Eighty-nine percent of long-distance trips were in personal vehicles; most of the other trips (7 percent) were by airplane (figure F). For 28 percent of the long-distance miles traveled and 63 percent of the trips, people stayed within their home state. International travel accounted for only 1 percent of long-distance trips but was 14 percent of total miles traveled.
Among other variables affecting the way people travel are income, gender, and age. For instance, both the number of daily and long-distance trips increases with household income. On average, people in households earning $100,000 or more made 13 long-distance trips, while those in households earning less than $25,000 made 6 long-distance trips. For daily travel, the differences are not as great. People in $100,000-income households took an average of 4.6 trips per day; those living in households earning less than $25,000 averaged 3.5 trips per day. Older adults do not travel as often or as far as do younger adults but rely as heavily on personal vehicles. However, people aged 65 and older make 55 percent of their daily trips between 10 a.m. and 4 p.m., while daily trips of people 19 to 64 years old peak 3 times a day: early morning, noon, and early evening.
Proximity to transportation options can also affect modal choices that people make. A geospatial analysis conducted by BTS in early 2003 showed that over 94 percent of rural residents in the United States live within a 25-mile radius of an intercity rail station, an intercity bus terminal, or a nonhub or small airport or within a 75-mile radius of a large or medium hub airport.
Comparing travel costs, by mode, of intracity and intercity trips is challenging because not all such costs are currently measured in the same way. BTS has developed a new method of computing price indexes for air travel that might one day serve as a model for producing price indexes for other modes.
BTS released initial data from its Air Travel Price Index (ATPI) in March 2004. The research phase of ATPI includes three indexes: one covering U.S. origin flights, one for foreign origin flights, and a third that is a combination of the first two. A comparison of the official BLS Airline Fare Index (of the U.S. Consumer Price Index) and the ATPI “U.S. origin only” index between the fourth quarters of 1998 and 2003 shows that the ATPI increased 7 percent while the BLS index rose 12 percent. The difference may be because the ATPI accounts for special discount fares that involve differential pricing, while the BLS measure does not, and other factors (figure G).
On average, U.S. households spent $7,825 (in chained 2000 dollars)12 on transportation (including vehicle purchases) in 2002 compared with $5,849 in 1992, an increase of 34 percent. Costs related to motor vehicles rose 36 percent between 1992 and 2002, while other transportation expenditures increased 6 percent. Transportation costs were 19 percent of all household expenditures in 2002; only housing cost more (33 percent).
Driving an automobile 15,000 miles per year cost 51¢ per mile in 2002, or 13 percent more than it did in 1992, when total costs were 45¢ (in chained 2000 dollars). For those using transit, the average fare ranged from 17¢ to 19¢ per passenger-mile (in chained 2000 dollars) between 1992 and 2002. Increases in fares per passenger-mile for some types of transit service were offset by lower fares per passenger-mile for other types.
On average, intercity trips via Amtrak cost 23¢ per revenue passenger-mile in 2002, up 44 percent from 16¢ per revenue passenger-mile in 1993 (in chained 2000 dollars). Meanwhile, average intercity Class I bus fares rose 23 percent, from $23 to $28, between 1992 and 2002 (in chained 2000 dollars).
While there are several thousand transit authorities in the United States, 30 of them served 43 percent of the resident population in 2002. Transit use continues to be concentrated in specific markets, such as communities where households do not tend to own cars, in certain large cities, and among lower income households. According to the 2001 NHTS, approximately 40 percent of all daily transit trips are work related.
Transit service can be measured in a variety of ways, including passenger-miles of travel and linked and unlinked trips.13 There were 45.9 billion transit pmt in 2002 compared with 37.2 billion pmt in 1992, an increase of 24 percent. As they have historically, buses had the largest pmt share in 2002, generating 19.5 billion pmt or 43 percent of all transit pmt (figure H).
Measured in unlinked trips, transit ridership has grown 17 percent since 1992 to 9.0 billion unlinked trips in 2002. Bus ridership comprised the majority of unlinked trips (5.3 billion) in 2002. However, rail transit ridership, with 3.4 billion trips in 2002, posted stronger growth (31 percent) between 1992 and 2002. Approximately 78 percent of all unlinked transit passenger trips (7.0 billion trips in 2002) were within the service area of only 30 transit authorities. New York City alone accounted for 30 percent of all transit trips in 2002.
The nationwide fleet of ADA-compliant lift- or ramp-equipped transit buses increased to 94 percent (to 64,407 buses) in 2002 from 52 percent of the bus fleet in 1993. In 2002, 53 percent or 1,506 rail transit stations were ADA14 accessible.
Repairs to vehicles, vessels, aircraft, and other transportation equipment, as well as roads, bridges, and other infrastructure, can impact the schedules of people and movement of goods. Data on these repair frequencies could help planners reduce the disruption repairs can cause. Unfortunately, data are not readily available to properly characterize the frequency of repairs for vehicles and infrastructure of most modes. There are a number of reasons for this lack of data.
In some cases where repair data are available, establishing a link to service interruptions can be problematic. In other cases, maintenance cost data are available (e.g., airlines and highways), but, again, the connection between costs and frequency and, thus, interruptions of service are not clear. Annual data are available on U.S. domestic vessel fleet capacity, but capacity results from market and other factors as well as repair downtime.
Most of the vehicle repair data for the trucks and buses operated by the nation’s more than 662,000 motor carriers are not public information. A surrogate measure is data on highway truck inspections. Over 2.1 million roadside truck inspections were completed in 2003, up 9 percent since 1993. The percentage of inspected trucks taken out of service declined from 26 percent in 1993 to 23 percent in 2003.
Work zones on freeways, an indicator of maintenance activity, cause an estimated 24 percent of the nonrecurring delays on freeways and principal arterials. The level of highway maintenance funding is an indirect measure of the amount of maintenance activity. Funding for highway maintenance increased by 15 percent (in constant 1987 dollars)15 between 1990 and 2001. Pavement resurfacing represented just over half (51 percent) of the miles of federal-aid roads undergoing federally supported construction or maintenance in 2001, up from about 42 percent in 1997.16
Class I railroad companies maintained 170,048 miles of track in 2002, down from 190,591 miles of track in 1992. In 2002, rail companies replaced 636,000 tons of rail (27 percent fewer than in 1992) and 13.1 million crossties (3 percent fewer than in 1992) (figure I). Railroads also periodically replace or rebuild locomotives and freight cars. On average, new and rebuilt locomotives made up 4 percent of Class I railroad fleets between 1992 and 2002.
Transit service17 interruptions due to mechanical failures remained relatively level from 1995 through 2000,18 averaging between 18 and 19 mechanical problems per 100,000 revenue vehicle-miles.
Natural disasters, accidents, labor disputes, terrorism, security breaches, and other incidents can result in major disruptions to the transportation system. Although a comprehensive account of these interruptions has not been undertaken nor data compiled on them, numerous studies and other analyses have sought to evaluate the effects of individual events on the transportation system. Terrorist attacks and security alerts have affected transportation services for decades. After the terrorist attacks of September 11, 2001, for instance, all commercial flights scheduled for September 12 were canceled and full service only gradually returned in the following weeks. Labor disputes can also disrupt transportation. A labor lockout in fall 2002 shut down all west coast ports for 10 days. Shipments by retailers, manufacturers, automakers, and the agricultural sector were particularly impacted.
Crashes involving motor vehicles and other transportation accidents in the United States result in tens of thousands of fatalities and millions of injuries each year. The number of fatalities and injuries per year represents a common means for evaluating the safety of each transportation mode. Presenting data in the form of the number of fatalities or injuries per 100,000 residents or by passenger-miles or vehicle-miles of travel can enable useful comparisons across time and modes. However, care must be taken in doing so, because definitions of fatalities and injuries vary by mode and estimates of vmt and, especially, pmt are inexact.
There were more than 45,000 fatalities related to transportation in 2002, almost 16 fatalities per 100,000 U.S. residents. This is the same rate as in 1992, when there were just over 42,000 deaths. About 94 percent of all transportation fatalities in 2002 were highway-related.
An estimated 3.0 million people suffered some kind of injury involving passenger and freight transportation in 2002. Most of these injuries, about 98 percent, resulted from highway crashes. However, injuries per pmt for most highway vehicle types declined between 1992 and 2002. One exception was the rate for light truck occupants, which rose 13 percent, from 45 per 100 million pmt in 1992 to 51 per 100 million pmt in 2002.
A BTS analysis of motor vehicle-related injury data for 200219 shows that there were sharp peaks in injuries associated with youth. For motor vehicle occupants and motorcyclists, the peak spanned ages 15 to 24 years. Young males exhibited a substantially greater peak in serious injuries than did young females (figure J). In addition, the percentage of injuries classified as serious was greater for motorcyclists (21 percent of all motorcyclist injuries were serious), pedestrians (19 percent), and pedalcyclists (13 percent) than it was for motor vehicle occupants (7 percent).
Motor vehicle crashes in the United States cost an estimated $231 billion in 2000 (in 2000 dollars), about $820 per person or 2 percent of the Gross Domestic Product (GDP). The largest components of the total cost (26 percent each) are market productivity—the cost of foregone paid labor due to death and disability—and property damage.
As people travel and freight is transported, damage can occur to the human and natural environment. Transportation also impacts the environment when transportation equipment and fuels are produced and infrastructure is built, during repair and maintenance of equipment and infrastructure, and when equipment and infrastructure are no longer usable and are discarded and dismantled. The extent of damage throughout these life cycles of transportation fuel, equipment, and infrastructure can vary by mode. In all cases, actual impacts on the human and natural environment are dependent on ambient levels or concentrations of pollutants and rates of exposure.
Transportation vehicles and vessels in 2001 emitted 66 percent of the nation’s pollution from carbon monoxide (CO), 47 percent of nitrogen oxides (NOx), 35 percent of volatile organic compounds (VOC), 5 percent of particulates, 6 percent of ammonia, and 4 percent of sulfur dioxide. Highway vehicles emitted almost all of transportation’s share of CO emissions in 2001, 79 percent of the NOx, and 78 percent of all VOC. With the exception of ammonia, emissions by transportation of these types of air pollutants have declined since 1991.
Transportation emissions of greenhouse gases (GHGs) grew 22 percent between 1992 and 2002, while total U.S. emissions rose 14 percent to 6,934.6 teragrams of carbon dioxide (CO2) equivalent. Of this, 27 percent were emitted by transportation. Nearly all (97 percent) of CO2 emissions—the predominant GHG—are generated by the combustion of fossil fuels. Transportation was responsible for 31 percent of all U.S. CO2 emissions in 2002 (figure K). Transportation CO2 emissions grew 21 percent between 1992 and 2002.
Transportation-related sources typically account for most oil spills into U.S. waters reported each year to the U.S. Coast Guard. For instance, transportation’s share of the reported total volume of oil spilled between 1991 and 2001 varied from a high of 97 percent (in 1996) to a low of 77 percent (in 1992). The volume of each spill varies significantly from incident to incident. One catastrophic incident can, however, spill millions of gallons into the environment.
Transportation can also affect human health and the environment when hazardous materials accidents occur. Transportation firms reported more than 15,300 hazardous materials incidents in 2002.20 These incidents resulted in 7 deaths and 129 injuries, compared with annual averages of 22 deaths and 419 injuries between 1992 and 2002. During that period, the number of reported hazardous materials incidents increased. However, much of the increase may be attributed to improved reporting and an expansion of reporting requirements.
Two major components of the transportation system—vehicles and infrastructure—are prone to deterioration due to wear, aging, and damage. Measures of the net capital stock of the transportation system—the value in dollars of vehicles, infrastructure, and other components—provide comprehensive indicators that combine system condition (quality) with capacity (quantity) and allow for comparisons across modes.
Highway-related capital stock (highway infrastructure, consumer motor vehicles, and trucking and warehousing) represented the majority ($2,432 billion in chained 2000 dollars) of the nation’s transportation capital stock in 2001, rising 27 percent since 1991. The combined value of privately owned capital stock ($650 billion in 2001) for other individual modes of the transportation system, including rail, water, air, pipeline, and transit, is less than the value of consumer motor vehicles alone ($855 billion). Between 1991 and 2001, the capital stock value of transportation services (a component of all modes) rose 94 percent, the most rapid growth of all capital stock components. The only modes with declining values during the period were water transportation (down 4 percent) and railroad transportation (down 6 percent).
Other infrastructure data reflect qualitative evaluations of the pavement and associated structures. The condition of highways, bridges, and airport runways has mostly improved in recent years. The percentage of rural Interstate mileage in poor or mediocre condition declined from 35 percent in 1993 to 12 percent in 2002. However, while poor or mediocre urban Interstate mileage decreased from 42 to 28 percent during this same period, urban minor arterial and collector conditions worsened. Of the nearly 600,000 roadway bridges existing in 2002, 14 percent were deemed structurally deficient and 14 percent functionally obsolete (figure L). Ten years earlier, about 35 percent of bridges were either structurally deficient or functionally obsolete. At the nation’s commercial service airports, pavement in poor condition declined from 3 percent of runways in 1993 to 2 percent in 2003. For the larger group of several thousand National Plan of Integrated Airport Systems airports, poor conditions existed on 4 percent of runways in 2003, down from 7 percent in 1993.
The age of various transportation fleets is another measure of condition, although not a very precise one. The equipment in air, rail, highway, water, and transit transportation fleets varies widely in terms of scheduled maintenance, reliability, and expected life span. Additional information, such as fleet maintenance standards, actual hours of vehicle use, and durability, would provide a more thorough means for analyzing the condition of a vehicle fleet and comparing fleets across modes.
The median age of the automobile fleet in the United States has increased 20 percent since 1992. The median age of the truck fleet,21 by contrast, began to increase in the early 1990s but has been declining since 1997 as new purchases of light trucks (including SUVs, pickups, and minivans) have increased substantially.
The age of transit vehicles varies by transit and vehicle type. For instance, ferryboat fleets have aged, while the average age of full-size transit buses and light-rail vehicles has decreased between 1991 and 2001. Similarly, the age of vessels varies by type. While 30 percent of the overall U.S. flag vessel fleet was 25 years old or more in 2001, 55 percent of towboats and 46 percent of tank and liquid barges were 25 years old or older in 2001 (figure M).
The average age of Amtrak locomotives was 14 years in fiscal year 2001, up 8 percent since fiscal year 1991, while the average age of Amtrak railcars declined by 2.5 years during the same period. Of the 20,503 Class I freight locomotives in service in 2002, 47 percent were built in 1990 or later. While these data on rail equipment are publicly available, data on the condition of infrastructure are not released by the nation’s private railroads.
Finally, the average age of all U.S. commercial aircraft was 12 years in 2001, up from 11 years in 1991. During the 1990s, the average age of aircraft belonging to the major airlines (a subset of all commercial aircraft) was one year younger but in 2001 these aircraft also averaged 12 years.
Transportation contributes to economic activity and to a nation’s global competitiveness as a service, an industry, and an infrastructure. It affects the price competitiveness of domestic goods and services because final market prices reflect transportation costs.
U.S. prices for transportation goods and services in 200022 were relatively lower than prices in 11 out of 24 Organization for Economic Cooperation and Development countries. However, the nation’s top two overall merchandise trade partners, Canada and Mexico, had lower relative prices in 2000 than the United States.
The United States traded $300 billion worth (in current dollars)23 of transportation-related goods (e.g., cars, trains, boats, and airplanes and their related parts) in 2002 with its partners. As is the case with its overall international trade, the United States had a merchandise trade deficit in transportation-related goods (with an excess of imports over exports) totaling $82.1 billion in 2002. The trade deficit has grown over the years, reflecting far greater imports than exports in the automotive sector. There is, however, a surplus in the aircraft sector.
U.S. trade in transportation services in 2002 totaled $105.4 billion (in current dollars). The United States had a surplus in transportation services from 1990 through 1997. Then, between 1997 and 1998, imports increased 7 percent while exports decreased 5 percent, resulting in a $4.6 billion deficit. This transportation services deficit continued to grow, reaching $13.9 billion in 2002 (figure N).
Transportation comprises a sizable segment of the U.S. economy. Total transportation-related final demand rose by 42 percent between 1992 and 2002 (in chained 2000 dollars), from $759.3 billion to $1,076.9 billion. This measure—the value of transportation-related goods and services sold to the final users—is a component of GDP and a broad measure of the importance of transportation to the economy. In 2002, the share of transportation-related final demand in GDP was 11 percent compared with 10 percent in 1992.
The contribution of for-hire transportation industries to the U.S. economy, as measured by their value added (or net output), increased (in chained 2000 dollars) from $206.4 billion in 1991 to $300.2 billion in 2001. In the same time period, this segment’s share in GDP fluctuated slightly, increasing from 2.9 percent in 1991 to 3.2 percent in 2000 before declining to 3.0 percent in 2001. This is also a component of GDP but cannot be added to transportation final demand because the two measures reflect different approaches (supply-side and demand-side) to assessing the relationship between transportation and the economy.
In addition to knowledge about transportation’s relationship to GDP, a monthly index of changes in freight and passenger activity in the economy is now available. The new, experimental BTS Transportation Services Index (TSI) rose to 122.5 in March 2004, its highest level since January 1990.24 The separate freight TSI rose to 123.3, while the passenger TSI was at 120.5 in March 2004 (figure O).
Governments collect revenues and spend money on transportation-related infrastructure and equipment. Federal, state, and local government transportation revenues targeted to finance transportation programs25 increased 39 percent from $90.9 billion in 1990 (in chained 2000 dollars) to $125.9 billion in 2000 (figure P).
Spending on building, maintaining, operating, and administering the nation’s transportation system by all levels of government totaled $167.5 billion in 2000 (in chained 2000 dollars). Among all modes of transportation, highways receive the largest amount of total government transportation expenditures. In 2000, this amounted to $104.0 billion and accounted for 62 percent of the total.
Gross government transportation investment,26 including infrastructure and vehicles, is a measure of the building of new public transportation capital. As a major component of the nation’s total transportation capital stocks, gross investment has risen steadily over the last decade from $67.4 billion in 1990 to $86.1 billion in 2000, an increase of 28 percent (in chained 2000 dollars).
The transportation sector used 17 percent more energy in 2003 than in did it 1993. Still, transportation energy use has grown more slowly than GDP during the period, indicating that the U.S. economy is gradually becoming less energy intensive and, thus, less vulnerable to changes in energy prices. Over 97 percent of all transportation energy consumed in 2002 came from petroleum. Total U.S. petroleum usage increased 15 percent between 1992 and 2002, with transportation responsible for 84 percent of that rise.
Transportation fuel prices experienced short-term fluctuations (in chained 2000 dollars) between 1993 and 2003. However, per capita vehicle-miles traveled for all modes of transportation increased almost every year. For instance, between 1993 and 2002,27 per capita highway vmt rose 12 percent, while that of large air carriers grew 22 percent.
Passenger travel (pmt per British thermal unit—Btu) was 1.0 percent more energy efficient in 2001 than in 1991, mainly due to gains by domestic commercial aviation. (Improved aircraft fuel economy and increased passenger loads resulted in a 26 percent gain in commercial air passenger energy efficiency between 1991 and 2001.) Freight energy efficiency (ton-miles per Btu) declined 5.4 percent from 1991 to 2001. The decline in freight energy efficiency occurred as a result of a 1.8 percent annual average growth in ton-miles paired with a relatively rapid annual rise of 2.4 percent in freight energy consumption over the period (figure Q).
Data collection, compilations, and analyses by BTS are focused on five core transportation data areas: freight, passenger travel, air transportation, economic, and geospatial. The previous October 2003 edition of this Transportation Statistics Annual Report (TSAR) series presented an overview of why these data are important to the transportation community, reviewed the existing data, and presented possible options for filling crucial data gaps. This edition of TSAR expands on that presentation by providing information on how BTS programs and projects are filling data gaps and improving the state of transportation statistics.
Meeting the variety and changing needs of the U.S. freight community and policymakers can be challenging for data providers. For many years, the Commodity Flow Survey has been the principal national freight flows data source. It was conducted in 1993, 1997, and 2002 as a partnership between BTS and the U.S. Census Bureau (figure R). CFS 2002 preliminary data were released in December 2003, and final data are expected in December 2004. To better meet data needs, BTS is working with others in the Department of Transportation (DOT) and the broader transportation community to plan a National Freight Data Program, which will provide enhanced freight flow data and integrated information collected from a variety of sources.
International freight flows data are important not only for tracking the growth of imports and exports but also for assessing domestic transportation requirements and impacts of trade. In May 2004, BTS completed the International Trade Traffic Study on domestic highway movements associated with international trade. The work was requested of BTS by the U.S. Congress in the Transportation Equity Act for the 21st Century. Two BTS data programs disseminate continuing, detailed information on transportation aspects of U.S. trade with Canada and Mexico. Border Crossing Data counts incoming vehicles, containers, passengers, and pedestrians for land gateways on the U.S.-Canadian and U.S.-Mexican borders. The Transborder Freight Data program has been providing monthly mode-specific trade data on surface modes, such as rail, truck, and pipeline, since 1993; and starting in 2004, BTS added air and waterborne mode data. Several federal agencies are working to put in place an International Trade Data System (ITDS), aimed at accelerating the phase-in of electronically filed trade documents. BTS is working with other DOT operating administrations and the ITDS managers at U.S. Customs and Border Protection of the Department of Homeland Security to ensure that ITDS will provide transportation-related data.
Knowing how, why, when, and where people in the United States travel is one of the most basic data needs of transportation policymakers, planners, and others. Most recently, data to understand how people use the transportation system for local and long-distance travel was generated by BTS and the Federal Highway Administration in the 2001 National Household Travel Survey28 (2001 NHTS) (figure S). For three years, BTS conducted the Omnibus Household Survey on a regular basis to ascertain people’s usage of the country’s transportation system. Data were also gathered on what people think about the system and to gauge public satisfaction with government programs.
Across the nation, metropolitan planning organizations are responsible for assuring that transportation planning meets the needs of their communities, including those of local residents and businesses. How people get from home to work and back and how these patterns change over time is essential data for transportation planners at the state and local level.
Various government entities and associations cooperate to disseminate state-, county-, and city-level journey-to-work (JTW) data collected with each decennial census. BTS provides statistical quality assurance expertise to the project team producing the Census Transportation Planning Package 2000 and is responsible for distribution of the data. A more robust provision of JTW data may arise from a Longitudinal Employer-Household Dynamics pilot program, initiated by the U.S. Census Bureau. The aim is to demonstrate the potential for linking existing economic administrative records with survey demographic data. BTS is participating in the pilot by conducting research to developthe necessary detailed origin and destination component. Finally, while the 2001 NHTS was primarily a national sample, an additional 40,000 households were surveyed from 9 jurisdictions (i.e., 4 urban areas, 4 states, and part of Kentucky), not only assisting these jurisdictions directly but also providing valuable insights at the national level.
Some transportation modes can be underrepresented in major surveys. Groups such as the elderly and disabled have special needs. Other people may reside in areas not well served by public transportation. BTS has augmented data on these and other special transportation issues with more specific surveys and studies, such as the National Survey of Pedestrian and Bicyclist Attitudes & Behaviors(with the National Highway Traffic Safety Administration); the 2002 National Transportation Availability and Use Survey, which surveyed people with and without disabilities; and a geospatial study of access to Scheduled Intercity Transportation by the nation’s rural population.
Transportation, a major U.S. industry, is multifaceted. It includes, for instance, carriers that are in the business of transporting people and goods (“for hire”) and other firms that use their own fleets of trucks or other vehicles to transport their own goods and people (“in house”). BTS collects various sets of modal data from the for-hire segment of the transportation industry, such as Airline Financial and Operating Statistics of both passenger and freight components of the airline industry and Motor Carrier Financial and Operating Statistics from Class I and II trucking and bus firms.
Transportation’s contribution to the U.S. economy can be measured in several ways. On a value-added basis, about 3.2 percent of the economy is produced by firms in the for-hire transportation industry, such as trucking, railroads, and waterborne shipping. In-house trucking services contribute another 1.0 percent or more. Work underway at BTS on Transportation Satellite Accounts will determine the full contribution of transportation services to the economy by developing data on the contribution of other modal in-house transportation services and a methodology to annually update the data.
After a three-year development phase, BTS released its experimental Transportation Services Index in March 2004. The TSI is a monthly, seasonally adjusted measure of the volume of services performed by the for-hire transportation sector. A comprehensive modal set of Capital Stock data, which help policymakers assess transportation investment needs, are not currently available (figure T). BTS is developing values for publicly owned airport and airway capital stocks, waterways, and transit systems that will augment capital stock data produced annually by the Bureau of Economic Analysis for modes such as trucking, air, and railroad transportation and highways and streets. Multifactor Productivity (MFP) provides a more comprehensive view of productivity than does labor productivity, a commonly used measure. The Bureau of Labor Statistics currently produces transportation MFP data for the railroad and air transportation industries. BTS is developing the methodology for and anticipating the production of MFP data for other transportation industries, such as trucking.
BTS developed the Air Travel Price Index (ATPI) to improve on traditional air travel cost indexes that are complicated by the variety of discount fares airlines now offered directly and through the internet and by frequent flyer programs. The ATPI applies the statistical methodology of a price index to measure changes in airfares. BTS released the still experimental ATPI data series in March 2004 and plans to issue quarterly updates.
As people travel and freight is transported, damage can occur to the human and natural environment. A BTS-managed project for the DOT Center for Climate Change and Environmental Forecasting, will assess the feasibility of developing a Transportation Greenhouse Gas Intensity of the Economy index. This study is expected to provide data and information on the validity of various measurements including an aggregate transportation measure. BTS is also assisting the DOT Center for Climate Change and Environmental Forecasting with the geographic information system component of a research project to better understand the impact of climate change and variability on the U.S. transportation system in the Gulf Coast region.
Under the Government Performance and Results Act, each federal agency must develop a performance plan and report annually on its progress. BTS assists in the preparation of DOT’s Performance Plan by providing performance measurement and statistical methodology support to the Office of the Secretary of Transportation and DOT’s operating administrations.
Managing raw data can be time consuming and resource intensive. Improvements in data analysis tools can reduce those costs as well as increase the quality of the analysis. The geographic relationships between freight movements and infrastructure can be displayed graphically by GeoFreight, a new tool produced by BTS, the Federal Highway Administration, and DOT’s Office of Intermodalism (figure U). Another GIS product produced by BTS, the National Transportation Atlas Database (NTAD), is a set of nationwide geographic databases of transportation facilities, transportation networks, and associated infrastructure.
The quality and utility of transportation data and the datasets can be problematic. Using an intra-agency committee process, BTS developed the statistical portion of DOT’s “Information Dissemination Quality Guidelines.” The result was a comprehensive set of guidelines that cover all aspects of the data-collection process from planning through dissemination. Under the BTS Data Quality Review program, the agency has conducted several in-depth assessments of DOT data systems, providing data managers with recommendations and suggestions for data quality improvements.
People gain needed information in a variety of ways. Satisfying that need means providing information in multiple formats. The BTS TranStats website provides downloadable data from over 100 transportation databases as well as links to many transportation datasets stored on other agency websites. For those in the transportation community who want quick access to already compiled multimodal data, BTS has produced a National Transportation Statistics (NTS) document since 1993. Collected from a variety of sources, the NTS provides, in print and online versions, over 190 tables of the most frequently used transportation data.
Relevance and other measures of progress are often determined by comparing results. Between 2001 and 2003, BTS produced a series of individual State Transportation Profiles covering all 50 states and the District of Columbia. The profiles provide—through tabular data—a picture of each state’s infrastructure, freight movement and passenger travel, safety, vehicles, economy and finance, and energy and environment. A summary version will be updated regularly for inclusion in the NTS.
Along with other federal agencies, BTS participates in the North American Transportation Statistics Interchange, a collaboration between transportation and statistical agencies of the United States, Canada, and Mexico. Its mission is to raise the general awareness and improve the quality, relevance, and comparability of transportation data and information across North America. A tri-country transportation database, produced by the Interchange, is expected to go online by the end of 2004.
Advancing statistical methods and standards and ensuring the accuracy, reliability, and relevance of transportation data is a continuing process. It requires the sharing of the latest research among the transportation statistics research community. BTS helps to enable this process with the production and dissemination of its Journal of Transportation and Statistics, a peer-reviewed international journal that encourages the application of advanced statistical methods to transportation problems. The completely digital National Transportation Library provides a full range of information access services to researchers as well as others in the transportation community.
The preceding overview shows that the nation has a wealth of available transportation indicators data, but the data are not always comparable nor are they complete. Fortunately, many accomplishments and work underway are succeeding in filling critical transportation data needs. Through its own efforts and in collaboration with others throughout the transportation community, BTS is contributing value to the state of transportation statistics, especially within the focused core areas of freight, passenger travel, air transportation, economic, and geospatial data.
1 See 49 U.S. Code 111(c)(1). Topics 1 through 11 come from the Intermodal Surface Transportation Efficiency Act of 1991; topic 12 was added by the Transportation Equity Act for the 21st Century of 1998.
2 The most recent CFS data collections occurred in 1993, 1997, and 2002.
3 All dollar amounts are expressed in chained 2000 dollars, unless otherwise specified, to eliminate the effects of inflation over time.
4GeoFreight was developed in 2003 by BTS, the Federal Highway Administration, and the Office of Intermodalism of the U.S. Department of Transportation.
5 BTS has been collecting on-time performance data since 1985 and in mid-2003 began collecting cause-of-delay data as well.
6 Vehicle loadings are based on equivalent single-axle loads.
7 These number and weight data, from the Vehicle Inventory and Use Survey (VIUS) conducted every five years, were the most recent available when this report was prepared. National summary VIUS 2002 data are expected in fall 2004.
8 Large combination trucks weigh more than 12 tons and have 5 or more axles.
9 1998 is the first year for which data are available.
11Personal vehicles include cars, vans, SUVs, pickup trucks, other trucks, recreational vehicles, and motorcycles.
12 All dollar amounts are expressed in chained 2000 dollars unless otherwise specified to eliminate the effects of inflation over time.
13 For a discussion of linked vs. unlinked trips, see section 7 in chapter 2.
14 ADA refers to the Americans with Disabilities Act of 1990.
15 Instead of chained 2000 dollars, these Federal Highway Administration data are published in constant 1987 dollars.
16 1997 is the earliest year for which these data are available.
17 See detailed definitions of the type of transit equipment included in section 8 in chapter 2.
18 Data prior to 1995 and later than 2000 were collected using different definitions of what constitutes an interruption of service and are not comparable.
19 This analysis was based on data from the U.S. Consumer Product Safety Commission’s National Electronic Injury Surveillance System. Due to methodological differences, these data are not necessarily consistent with other injury data in this report that come from the U.S. Department of Transportation, National Highway Traffic Safety Administration’s National Automotive Sampling System General Estimates System.
20 See section 10 in chapter 2 for a definition of a reported incident.
21 This includes all truck categories: light, heavy, and heavy-heavy.
22 2000 is the most recent year for which comparable international data were available at the time this report was prepared.
23 All dollar amounts in this section are in current dollars. While it is important to compare trends in economic activity using constant or chained dollars to eliminate the effects of price inflation, it is not possible to do so in this instance (see notes on chapter 2 figures and corresponding tables in appendix B).
24 The TSI is a chained-type index where 1996 = 100.0.
25 See section 14 in chapter 2 for detailed descriptions of the government revenues included.
26 See section 14 in chapter 2 for detailed descriptions of transportation investments.
27 At the time this report was prepared, data for highway and aircraft vmt were only available through 2002.
28 This survey was conducted between March 2001 and May 2002.