Transportation Economics in the 21st Century - US Department of Transportation (DOT) Data

The Department of Transportation (DoT) has a variety of data sources publicly available for researchers. For researchers interested in a broad transportation sector, a natural starting place is the Bureau of Transportation Statistic’s (BTS) sectoral profile. The BTS provides overviews for 11 major sectors: air carriers, automobiles, buses, general aviation, highways, natural gas pipelines, oil pipelines, rail, transit, trucks, and water transport. These profiles cover the sectors’ inventory, finances, safety, and performance, among other topics. For those interesting in specific topics, the DoT provides more targeted data sources on the transportation capital stock, the system usage, safety metrics, the economics of the transportation sector, energy usage, and pollution, each discussed below. Most of these data are decadal back to 1960, with data updated annually after 1995. Newer subsectors, such as hybrid and electric vehicles necessarily have shorter time series. Data is primarily nationally aggregated, and often disaggregated by subtype but not geography. These are summary tables, and provide a useful starting place for identifying and using some of the larger datasets offered by the DoT.

Data on the U.S. transportation sector’s capital stock can be divided into resources on the physical extent of infrastructure, and vehicle, aircraft, and vessel inventory. For an overview of infrastructure over time, the System Mileage within the United States tracks the stock of roads, rail, waterways, and pipelines. These infrastructure sources are often disaggregated by product type. For example, the U.S. Public Road and Street Mileage by Functional System table provides a time series on the extent of total public road mileage, and breaks it down by rural/urban location, as well as road types from major arterial interstates down to local roads. Taking stock of the mobile capital, researchers can find data on the Number of U.S. Aircraft, Vehicles, Vessels, and Other Conveyances, which provides an overview of the stock of craft moving along the physical network. Researchers can also find data on the flow of new conveyances into the transportation sector, either through sales or production, or entirely new subsectors such as hybrid and electrical vehicle sales. Finally, the DoT also releases data on the condition of infrastructure and inventory, such as the Average Age of Urban Transit Vehicles or the Condition of U.S. Bridges.  

In addition to data on the extent of the capital stock, the DoT has many resources on how we use the system. These resources can be divided into travel and goods movement, and physical performance. There are a wide variety of data sources tracking travel of people over time, such as U.S. Passenger Miles across a variety of modes, border crossings between the U.S. and either Mexico or Canada, and how people choose to commute. Similarly, the DoT tracks how goods flow over time, such as the U.S. Ton-Miles of Freight by mode,  the value of imports and exports crossing between the U.S. and Mexico or Canada, and even Worldwide Commercial Space Launches. While tracking the flows of people and goods, the DoT also monitors a variety of performance metrics. For example, if interested in travel delays, one can find time series  for the share of flights arriving on time, Amtrak’s delays, roadway congestion, and the cost of congestion, the latter two broken down across 100 urban areas.

The next category of DoT data covers safety issues. These include tables covering fatalities, accidents or injuries across many modes, as well as safety data particular to each mode. For example, in the aviation sector, one can track the number of items confiscated by screening agents at airports, while the highway safety data includes statistics on the types of DUI/DWI legislation by state. Safety data is broken up by air, highway, transit, railroad, water and pipeline sources.

The DoT also offers many data sources on the economic scope of the transportation sector, in four broad sections. The first section is transportation and the economy, which looks at the size of transportation sector, for example the U.S. Gross Domestic Product Attributed to Transportation Related Final Demand. The second section covers consumer expenditures and provides data on how people pay for transportation services. Here you’ll find data on average passenger fares across different modes, the relative price of gasoline, and the average cost of owning and operating a vehicle. The third section covers employment, productivity and revenues in the transportation sector. This holds data such as operating revenues by sector, wages and salaries in the transportation sector by industry (NAICS) or occupation (SOC). The final section covers government finance of the transportation sector, and has data on government expenditures and revenues from transportation, broken down by mode, as well as federal transportation grants and trust funds.

With energy an important input to transportation, the DoT also has a myriad of data sources on energy use in transportations. These fall into three categories. First, the DoT provides summary statistics from the Department of Energy on energy consumption by source, as well as petroleum production, imports, exports, consumption, and domestic demand. The next category covers energy consumption by mode, with data ranging from personal vehicle fuel consumption to energy use broken down by government agency and energy type. The third category covers energy intensity and fuel efficiency. These data are primarily cut by vehicle type, from air carriers to motorcycles.

The final major data type is pollution, and the DoT has data on air, water, noise, and solid waste pollution. By far the most extensive data type is on air pollution. The air pollution data sovers emissions standards for new vehicles by vehicle type, estimated emission rates by vehicle type, time series for emissions of important pollutants such as carbon monoxide, and even air pollution trends across 88 MSA’s. For water, noise and solid waste pollution, the DoT has data such as oil spills, highway noise barrier construction, and scrapped vehicles.