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Chapter 3: Passenger Transportation System and Reliability


In recent years some transportation modes have seen increases in use, whereas others have experienced decreases. From 2005 to 2011, motorcycle and bus travel increased by 77.4 and 97.8 percent, respecively, whereas car travel declined by 3.6 percent. The number of rail passengers increased as did the number of unlinked1 transit trips; however, airline passenger miles fell by more than 10 percent. The extent of the U.S transportation system also fluctuated.

The passenger transportation system is an interconnected network of highways, railroads, airports, public transit systems, and waterways that serves over 300 million U.S. residents and foreign visitors. Figure 3-1 depict the traffic (excluding large trucks and buses) on the National Highway System (NHS)2 in 2011. The majority of passenger vehicle traffic is concentrated in and around large cities. In 2011, 28.4 percent of passenger vehicle traffic was on the NHS (including Interstates). While the bulk (69.9 percent) of NHS mileage is rural, only 8.1 percent of passenger vehicle traffic occurred in a rural setting.

In 2011 peak-period congestion resulted in traffic slowing below posted speed limits on 13,500 miles of the nearly 224,000 miles of road that comprise the National Highway System and created stop-and-go conditions on an additional 8,700 miles.

In 2011 the Washington DC metropolitan area averaged 67 hours of average annual delay per auto commuter, the highest of any metropolitan area. This is 49 hours more than the average annual delay per auto commuter in 1982. Also in 2011, Los Angeles-Long Beach-Santa Ana, CA, experienced an estimated 61 hours of delay per auto commuter, tying with San Francisco-Oakland, CA, as the urban area with the second most average annual hours of delay.

Based on the number of domestic enplanements in 2012, 26 airport markets that accounted for at least 1 percent of total enplaned passengers were classified as large, whereas airport markets with 0.25–0.99 and 0.05–0.24 percent of total enplanements were classified as medium and small, respectively.

Airline enplanements (domestic and international) peaked in 2007 and bottomed in 2009 before starting a steady climb. Between 2009 and 2012, domestic enplanements rose 3.9 percent, and international enplanements rose 12.4 percent. In 2012 total enplanements remained 2.6 percent below the 2007 peak, with domestic enplanements down 5.4 percent, while international enplanements were up 9.5 percent.

Figure 3-4 Total Domestic Load Factor and Average Airfare, 1995–2012

Table Version

Figure 3-4 Total Domestic Load Factor and Average Airfare, 1995–2012

NOTE: Load factor calculated by dividing the total revenue passenger miles by available seat miles.

SOURCE: Airfare- Load Factors - U.S. Department of Transportation, EmEdjimurjE, Office of Airline Information T-100 Domestic Segment, available at , as of November 2013.

Since 2008, as airlines reduced capacity, flights have become more crowded and load factors have reached record levels (figure 3-4). Inflation-adjusted domestic airfares, as evidenced by the constant dollars trend line, dipped to a decade-low in 2009 before recovering through 2012, reversing a decline that actually began in 2000. In 2012 the average airfare was about $379, down from the year 2000 average airfare of $457 (constant dollars).

In 2012 the most traveled city pair by air was between San Francisco International Airport and Los Angeles International Airport (LAX), followed by LAX and John F. Kennedy International Airport. Average travel times have changed little for selected city pairs over the years.

All of the top 10 domestic air markets ranked by number of domestic enplanements experienced an increase in enplaned passengers from 2011 to 2012. New York City was the top market with 46.5 million domestic enplanements in 2012. Of the top 10 markets, the greatest percentage increase from 2011 to 2012 took place in San Francisco, up 5.9 percent, and the smallest percentage increase, 0.1 percent, took place in Houston.

Southwest carried the most passengers from domestic origins of any airline in 2011 and 2012, with 1.5 percent more passengers in 2012. Delta retained its second place ranking with a 2.8 percent increase in enplaned passengers from domestic origins in 2012. AirTran experienced the biggest percentage decline in the number of enplaned passengers from domestic origins of the top 10 airlines with 12.9 percent fewer passengers in 2012 than in 2011. JetBlue had the greatest percentage increase in enplaned passengers from domestic origins of the top 10 airlines with 9.2 percent more passengers in 2012 than in 2011.

Figure 3-5 U.S. Airport Delays by Cause: 2012

Table Version

Figure 3-5 U.S. Airport Delays by Cause: 2012

aSignificant meteorological conditions that delays or prevents the operation of a flight.
KEY: NAS = National Aviation System.
NOTE: Percents do not add to 100 due to rounding.
SOURCE: U.S. Department of Transportation, EmEdjimurjE, Office of Airline Information, available at emedjimurje.info as of October 2013.

In 2012, 18.1 percent (more than 1.1 million) of scheduled flights were delayed, canceled, or diverted. The leading cause for airline delay was aircraft arriving late, which accounted for 41.4 percent of total delay time in 2012. The term “aircraft arriving late” means that a previous flight with the same aircraft arrived late, causing the next flight to depart late.3 A flight is considered delayed when it arrives at the gate 15 or more minutes later than scheduled. Delays (and cancellations) attributable to the National Airspace System (NAS) refer to a broad set of conditions, such as nonextreme weather conditions, airport operations, heavy traffic volume, and air traffic control.

Among large airports, Newark had the highest percentage of flights delayed in 2012, with 34.5 percent of total flights delayed. San Juan, PR, had the most delayed flights for a medium sized airport in 2012, with 30.9 percent of flights delayed. Topping the list for the small airports category, with 38.1 percent of flights being delayed in 2012, was Baton Rouge, LA.

As shown here, flight cancellations are more likely to occur in the winter than any other time of the year due to the impact of snow and ice on flight operations. Nine of the top 10 months for flight cancellations occurred in the winter, the only exception being October 2012. The top three months for percent of weather-related cancellations were all in February.

Amtrak served a total of 517 stations in 2011.4 Twelve of the Nation’s 25 busiest Amtrak stations serve the Northeast Regional route. The busiest station within the entire Amtrak network is New York City’s Penn Station. The top 25 busiest stations are highlighted by total ridership.

In 2012 Amtrak achieved 83 percent on-time performance. A total of 21,384 hours of delay in 2012 occurred on track owned by Amtrak, compared to 46,584 hours of delay that occurred on track owned by another (host) railroad. Overall delay hours were down 7.9 percent from 2011 to 2012.

The New York metropolitan area registered 4.2 billion transit trips in 2012, far more than any other U.S. metropolitan area. The rail system (commuter rail, subway, or light rail) accounted for the majority of New York area transit trips (70.3 percent), while the bus system accounted for 28.8 percent. The Los Angeles metropolitan area had the second most transit trips in 2012, approximately 671 million, with the majority (81.2 percent) by bus. Analyzing numbers of transit trips is not the only measure of public transit usage; the 2012 American Community Survey shows how public transportation usage can  vary substantially from one major metropolitan area to another, with 31.1 percent of commuters taking public transportation to and from work in the New York metropolitan area compared to 5.9 percent of commuters taking public transportation in the Los Angeles area.

In 2011, based on results from the American Community Survey, 12.1 percent of the U.S. population self-identified as having a disability. The Americans with Disabilities Act (ADA) requires public transportation facilities to be readily accessible, without physical barriers that prohibit or restrict access by individuals with disabilities. The National Transit Database5 indicates, by transportation mode, the number of public transportation facilities compliant with the ADA mandate. The number of accessible stations has increased steadily since 1998. By 2011, 99.4 percent of bus stations and 90.8 percent of light rail stations were compliant with ADA, compared to 65.8 percent of commuter rail and 50.9 percent of heavy rail stations.

Since 1998 there has been an increase in the number of buses meeting ADA compliance in each category. Articulated buses, which pivot in the middle, have seen the greatest rise, with 95.4 percent ADA compliance by 2011.

In 2011 the top North American cruise destination was the Western Caribbean6, accounting for 27.1 percent of total cruise ship visits up from 25.9 percent in 2008. The
Bahamas were the second most visited cruise ship destination that year, accounting for 20.8 percent of cruise ship traffic. Compared to 2008, Mexico saw the greatest decrease in cruise ship traffic with roughly half as many departures occurring in 2011. The Bahamas and Bermuda saw the greatest increase in visits by cruise ships with 31.7 and 26.6 percent more departures, respectively (see table 3-11).

In 2010 approximately 53.4 million passengers used the ferry system in the United States. Washington, New York, and California had the greatest number of ferry passengers  accounting for 15.0, 6.8, and 7.7 percent of total passengers, respectively. Ferries in Washington, Louisiana, and Alaska carried the greatest proportion of vehicles with 26.9, 12.4, and 11.6 percent of total vehicle boardings, respectively. In 2010, Washington ferries carried approximately 15.4 million persons and 10 million vehicles.

In 2013 there were 111 facilities (approximately 1.5 percent) where connections to three modes were present.  Locations with access to three or four transportation modes tend to be in urban areas or in locations near or between major cities.

1 Unlinked trips for transit refer to the number of passengers who board public transportation vehicles. Passengers are counted each time they board vehicles no matter how many vehicles they use to travel from origin to destination.

2 The National Highway System includes the Interstate Highway System as well as other roads important to the nation’s economy, mobility, and defense.

3 For more information on Airline On-Time Performance and Causes of Flight Delays, refer to: http://emedjimurje.info/help/aviation/index.html

4 U.S. Department of Transportation, EmEdjimurjE, National Transportation Statistics, Table 1-7, available at as of January 2014.

5 The National Transit Database is administered by the U.S. Department of Transportation’s Federal Transit Administration. Data is collected yearly, for more information refer to:

6 Comprises the Caribbean coasts of Central America, from Yucatán in Mexico to northern Colombia, and the islands west of Jamaica.

Box 3-A Intermodal Passenger Connectivity Database

The Intermodal Passenger Connectivity Database (IPCD) is a nationwide databaes of passenger transportation terminals with data on the availability of connections among the various scheduled public transportation modes at each facility. The IPCD data covers the following types of passenger transportation terminals:

  • scheduled airline service airports;
  • intercity bus stations (includes stations served by regular scheduled intercity bus service such as Greyhound and Trailways, code sharing buses such as “Amtrak Thruway” feeder buses, supplemental buses that provide additional frequencies along rail routes, and airport bus services from locations that are outside of the airport Metropolitan Area);
  • intercity and transit ferry terminals;
  • light rail transit stations;
  • heavy rail transit stations; and
  • passenger rail stations on the national rail network serving both commuter rail and intercity rail services.

Of the approximately 7,200 passenger transportation terminals in the United States, 56 percent offer travelers the ability to connect among the scheduled passenger transportation modes. There are three basic types of linkups used to quantify the degree of connectivity at a facility. A facility is considered connected, or intermodal, when one of these options is either present or less than one block away:

  • intercity transportation and local transit,
  • two or more intercity modes, or
  • two or more local transit modes.

Where one of these three linkups occurs but at a distance slightly farther apart than one block, or the tim- ing/scheduling precludes a timely connection, the facility is considered nearly connected.

Updated: Wednesday, February 14, 2018