Washington, D. C., formally the District of Columbia

Infrastructure

Transportation

Main article: Transportation in Washington, D.C.

Metro Center is the transfer station for the Red, Orange, Silver, and BlueMetrorail lines.
There are 1,500 miles (2,400 km) of streets, parkways, and avenues in the District.^[195] Due to the freeway revolts of the 1960s, much of the proposed interstate highway system through the middle of Washington was never built. Interstate 95 (I-95), the nation's major east coast highway, therefore bends around the District to form the eastern portion of the Capital Beltway. A portion of the proposed highway funding was directed to the region's public transportation infrastructure instead.^[196] The interstate highways that continue into Washington, including I-66 and I-395, both terminate shortly after entering the city.
The Washington Metropolitan Area Transit Authority (WMATA) operates the Washington Metro, the city's rapid transitsystem, as well as Metrobus. Both systems serve the District and its suburbs. Metro opened on March 27, 1976 and, as of July 2014, consists of 91 stations and 117 miles (188 km) of track.^[197] With an average of about one million trips each weekday, Metro is the second-busiest rapid transit system in the country. Metrobus serves over 400,000 riders each weekday and is the nation's sixth-largest bus system.^[198] The city also operates its own DC Circulator bus system, which connects commercial areas within central Washington.^[199]

Union Station is a transportation hub for passengers on Amtrak, commuter rail lines, and the Washington Metro.
Union Station is the city's main train station and services approximately 70,000 people each day. It is Amtrak's second-busiest station with 4.6 million passengers annually and is the southern terminus for the Northeast Corridor and Acela Express routes. Maryland's MARC and Virginia's VRE commuter trains and the Metrorail Red Line also provide service into Union Station.^[200] Following renovations in 2011, Union Station became Washington's primary intercity bus transit center.^[201]
Three major airports serve the District. Ronald Reagan Washington National Airport is across the Potomac River from downtown Washington in Arlington, Virginia and primarily handles domestic flights. Major international flights arrive and depart from Washington Dulles International Airport, 26.3 miles (42.3 km) west of the District in Fairfax and Loudouncounties in Virginia. Baltimore-Washington International Thurgood Marshall Airport is 31.7 miles (51.0 km) northeast of the District in Anne Arundel County, Maryland.
According to a 2010 study, Washington-area commuters spent 70 hours a year in traffic delays, which tied with Chicago for having the nation's worst road congestion.^[202] However, 37% of Washington-area commuters take public transportation to work, the second-highest rate in the country.^[203] An additional 12% of D.C. commuters walked to work, 6% carpooled, and 3% traveled by bicycle in 2010.^[204] A 2011 study by Walk Score found that Washington was the seventh-most walkable city in the country with 80% of residents living in neighborhoods that are not car dependent.^[205]
An expected 32% increase in transit usage within the District by 2030 has spurred construction of a new DC Streetcar system to interconnect the city's neighborhoods.^[206] Construction has also started on an additional Metro line that will connect Washington to Dulles airport.^[207] The District is part of the regionalCapital Bikeshare program. Started in 2010, it is currently one of the largest bicycle sharing systems in the country with over 2,500 bicycles and more than 300 stations.^[208] The city is expanding a network of marked bicycle lanes which currently exist on 56 miles (90 km) of streets.^[209]