Kilometers of Public Roads and Streets in the United States by Type of Surface

KEY:  N = data does not exist.

^a 1960-95 data includes the 50 states and the District of Columbia; 1996-2008 data includes the 50 states, District of Columbia, and Puerto Rico; 2011-16 data includes the 50 states and the District of Columbia; 2017-18 data includes the 50 states, Puerto Rico (data may be incomplete), and the District of Columbia.

^b  Paved mileage includes the following categories: low type (an earth, gravel, or stone roadway that has a bituminous surface course less than 1" thick); intermediate type (a mixed...

System Kilometers Within the United States

KEY:  N = data do not exist; R = revised; U = data are not available.

^a All public road and street mileage in the 50 states and the District of Columbia. For years prior to 1980, some miles of nonpublic roadways are included. No consistent data on private road mileage are available. Beginning in 1998, approximately 43,000 miles of Bureau of Land Management Roads are excluded. 2010 Missouri and Wyoming's data are 2009.

^b Data represent miles of road owned (aggregate length of road, excluding yard tracks, sidings, and parallel lines...

Hazardous Materials Fatalities, Injuries, Accidents, and Property Damage Data

KEY: R = revised. 

^a The 1996 spike in Air Fatalities was due to the ignition of an undeclared cache of chemical oxygen generators in a flight over Florida that killed 110 people, according to the U.S. Department of Transportation Biennial Report on Hazardous Materials Transportation, 1996-1997. 

^bWater category includes only nonbulk marine. Bulk marine hazardous materials incidents are reported to the U.S. Coast Guard and are not included.

^cOther category includes freight...

Highway-Rail Grade-Crossing Safety

KEY: R = revised. 

^a 1970 data are not comparable to later years due to a change in the reporting system.

Highway Noise Barrier Construction

KEY: R = revised.

^a  A Type I barrier is built on a new highway project or a physically altered existing highway.

^b  A Type II barrier is built to abate noise along an existing highway (often referred to as retrofit abatement) and is not mandatory.

^c All other types of barriers are nonfederally funded.

^d Have not been assigned a year of construction or a cost.

Leaking Underground Storage Tank Releases and Cleanups

Amtrak On-Time Performance Trends and Hours of Delay by Cause

KEY:  N = data do not exist.

^a Routes outside the Northeast Corridor and under 750 miles in length.

^b Routes over 750 miles in length.

^c Amtrak changed its method for reporting delays in 2000.  Therefore, the data for 2000 and following years are not comparable with prior years.

^d Includes all delays that occur when operating on Amtrak owned tracks and all delays for equipment or engine failure, passenger handling, holding for connections, train servicing, and mail/baggage handling when...

Major U.S. Air Carrier Delays, Cancellations, and Diversions

Crude Oil and Petroleum Products Transported in the United States by Mode

KEY: N = data do not exist; R = revised.

Value of U.S. Exports to and Imports from Canada and Mexico by Transportation Mode

^aOther includes "flyaway aircraft" or aircraft moving under their own power (i.e., aircraft moving from the manufacturer to a customer and not carrying any freight), powerhouse (electricity), vessels moving under their own power, pedestrians carrying freight, and unknown and miscellaneous.

^bMail shipments data for several years prior to May 2004 were not compiled correctly resulting in undercounts.

^c Beginning in January 1996, new edit checks were added in the processing of the data. Because of these checks, the number of...