With two major airports and several regional air facilities, Houston ranks as a central transportation hub. Nearly 45 million passengers passed through the Houston Airport System in 2004. Passenger service is provided by all major domestic and international carriers at the George Bush Intercontinental Airport on the north side of the city, and by most major domestic carriers at the more centrally located William P. Hobby Airport about seven miles south of downtown. Ellington Field serves approximately 80,000 private and corporate passengers each year.
Houston is the crossroads for Interstate Highways 10 and 45. Other major highways serving Houston are I-610, US-59, US-290, US-90, SH-288, SH-225, Hardy Toll Road, Beltway 8, and SH-99. Amtrak passenger rail service to Houston is available on the Miami-Houston-Los Angeles routes. Greyhound and Kerrville Bus Company offer regular motor coach service. Visitors can now arrive in Houston via the ocean, as Norwegian Cruise Lines launched service from the Port of Houston in November 2003.
Automobiles constitute one of Houston's principal transportation headaches, although an ambitious transit program offers the hope of unsnarling some of the major traffic problems. An extensive commuter bus system operated by the Metropolitan Transit Authority of Harris County (METRO) provides service in the inner city and most outlying areas with a fleet of 1,595 buses covering 1,285 square miles of service area; in 2001 approximately 120 million passengers rode these buses. In 2004 METRO began operating a light rail system. Initially the line runs a 7.5 mile route through downtown Houston, but is scheduled to expand to 20 miles by 2012 and to 80 miles by 2025.