Overview of the Passenger Transportation System

The passenger transportation system is a network of highways, railroads, airports, public transit systems, and waterways that serves over 300 million U.S. residents and foreign visitors. It comprises more than 4 million miles of roads, 11,000 miles of transit rail directional route-miles, 21,000 miles of Amtrak routes, 11,000 airports, and about 25,000 miles of navigable waterways.

Public Roads and Vehicles

Composed of over 4.1 million miles of interstate highways, arterials, and local routes, the highway network has expanded in the last decade. Between 2000 and 2013, miles of public road grew by 4.6 percent and lane-miles increased by 5.3 percent, while traffic volume grew 8.0 percent. Local roads are by far the most extensive, comprising 2.8 million miles (69.2 percent of total system miles.) Interstate highways handled the highest volumes of traffic as measured by vehicle-miles traveled, 24.8 percent in 2013, but accounted for only 1.2 percent (about 47,500) of total system miles.

The National Highway System (NHS) is a network of about 230,000 miles of interstates and other roads essential to the Nation’s economy, defense, and mobility. While only 5.5 percent of the Nation’s total route mileage and 9.0 percent of the total lane-miles were on the NHS, these roads carried 54.9 percent of total vehicle-miles traveled in 2013. Passenger vehicle traffic on the NHS, excluding large trucks and buses, is concentrated in and around large cities. In 2011, 28.4 percent of passenger vehicle traffic was on the NHS. While the majority (69.9 percent) of NHS mileage is rural, only 8.1 percent of passenger vehicle traffic took place in a rural setting.

Road congestion is one of the major causes of travel time delay and negatively impacts transportation system reliability. In 2011 peak-period congestion resulted in traffic dropping below posted speed limits on 13,500 miles, or 6 percent, of the NHS. This congestion created stop-and-go conditions on an additional 8,700 miles of road.

The Planning Time Index (PTI) is a reliability measure that estimates the extra time one should plan for a trip. For example, for a PTI of 1.5, a traveler should allow 50 percent more time in order to arrive on time 19 out of 20 times. In other words, 30 extra minutes should be budgeted for a trip that would typically take 60 minutes in free flow conditions.

Based on PTI data collected from 18 cities between 2007 and 2012, travelers would have to plan a minimum of about 40 percent more travel time to arrive “on-time” for 19 out of 20 trips. From 2007 to 2012, roadway congestion improved, resulting in a drop in the PTI and an increase in highway reliability. Travel on highways was generally less reliable in winter than in summer months.

In the Nation’s urban areas, commuters spent 5.5 billion hours in congestion, wasting 2.9 billion gallons of fuel in 2011. This congestion cost the economy an estimated $121.2 billion. Overall measures of congestion delay and cost have increased since 2000, although the recession that ended in 2009 had a dampening effect on what had been a steady increase. Despite a slight decrease in delay per commuter, total delay increased from 4.5 to 5.5 billion hours.

In 2011 the Washington, DC, area averaged 67 hours of average annual delay per auto commuter. This delay was the highest of the 498 urban areas included in the study and 3.1 percent higher than in 2000. The Los Angeles-Long Beach-Santa Ana, CA, and San Francisco-Oakland, CA, urban areas both experienced an estimated 61 hours of delay per auto commuter and a 15.3 percent decrease from 2000.

Aviation

In 2013 there were over 540 certificated airports in the United States. These airports serve commercial air carriers and aircrafts seating more than 9 passengers. Over 18,000 additional airports across the Nation serve general aviation aircraft.

The U.S. airline passenger load factor—an indicator of capacity utilization—rose from 72.6 in January 2003 to 83.0 in January 2015. After the recent recession, the load factor generally increased because use, measured in revenue passenger-miles, increased at a faster pace than capacity, measured in available seat-miles. In December 2014 use and capacity returned to prerecession levels, reaching all-time, seasonally adjusted highs of 73.3 revenue passenger-miles and 88.4 available seat-miles.

During the last decade, U.S. airline on-time performance was at its lowest in 2007 when 26.6 percent of flights did not arrive on time. The percentage of delayed flights declined to 16.7 percent in 2012, before rising to 21.3 percent in 2014. The average length of flight delays remained above 50 minutes, averaging 57 minutes in 2014.

In 2014, 39.2 percent of the delayed arrivals were delayed for less than 30 minutes. Slightly fewer flights, 31.3 percent of delayed arrivals, were delayed between 30 and 59 minutes, while almost 10 percent of delayed arrivals were delayed for more than 2 hours.

Flight delays are caused by a variety of reasons, ranging from extreme weather to disruptions in airline carrier operations. The combined effects of nonextreme weather conditions, airport operations, heavy traffic volume, and air traffic control (i.e., National Aviation System) contributed to 23.5 percent of delays in 2014, a 10.0 percentage point improvement over 2004. Flight delays can ripple through the U.S. aviation system as late arriving flights delay subsequent flights. Late arrivals were the cause of 41.9 percent of delays in 2014.

Flight cancellations are more likely to occur in the winter due to the impact of snow and ice on flight operations. Nine of the top 10 months for flight cancellations between January 2003 and February 2015 occurred in the winter; the only exception was October 2012.

Among large airports, San Francisco International Airport had the highest percentage of flights delayed in 2014. Will Rogers World Airport, located in Oklahoma City, OK, had the most delayed flights for medium-sized airports, with 26.7 percent of flights delayed. Topping the list for small airports was Guam International Airport, with 33.3 percent of flights delayed.

Public Transit

More than 800 urban transit agencies and 1,500 rural and tribal government transit agencies offer transit service. Since 2000 rail transit (commuter rail, heavy rail, and light rail) has expanded to cover over 11,000 directional route-miles and include over 3,000 rail transit stations. Buses accounted for about half, 49.2 percent, of the over 136,000 transit vehicles in 2013.

Based on results from the American Community Survey, 12.6 percent of the U.S. population self-identified as having a disability in 2013. In 2013, 78.8 percent of transit stations complied with the Americans with Disabilities Act (ADA), which requires agencies to provide accommodations for individuals with disabilities at public transit facilities. The number of accessible stations has increased steadily since 2000. In 2013, 99.0 percent of bus stations and 88.1 percent of light rail stations were compliant with the ADA.

Passenger Rail

Amtrak is the primary operator of intercity passenger rail service in the United States. Amtrak operated over 21,300 route miles in 2012 and more than 500 stations that served 46 states and Washington, DC. Amtrak’s fleet of rail cars and locomotives decreased by 32.7 and 25.4 percent, respectively, from 2000 to 2010, but increased in 2012 since Amtrak is in the process of acquiring new equipment to replace its aging fleet.

In fiscal year (FY) 2014, Amtrak achieved 72.4 percent on-time performance, down 9.9 percentage points from the previous year. Delays were more likely to occur on track owned by another (host) railroad than on track owned by Amtrak. In FY2014 host railroads were responsible for 64.0 percent of delayed time, and Amtrak was responsible for 24.9 percent.