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...

Motor Vehicles Scrapped

KEY:  R = revised; U = data are unavailable.

Table has been discontinued. There will be no further data updates for this table due to source informational no longer being available.

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.

Number of People Residing in High Noise Areas around U.S. Airports

KEY:  dB = decibels; DNL = day-night sound level; R = revised.                                                                      

a Noise-level contours are graphical representations of noise levels on a map, similar to elevation...

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

KEY: R = revised.

U.S. Hazardous Materials Shipments by Hazard Class, 2017

KEY: U = data are unavailable or rounds to zero.