Houston’s freeway system includes 575.5 miles of freeways and expressways in the 10-county metro area. The State of Texas plans to spend $5.06 billion on Houston area highways between 2002 and 2007. Houston freeways are heavily traveled and often under construction to meet the demands of continuing growth. Interstate 45 south has been in a continuous state of construction, in one portion or another, almost since the first segment, the Gulf Freeway—Texas's first freeway—was opened in 1948. Texas Department of Transportation (TxDOT) planners have sought ways to reduce rush hour congestion, primarily through High-occupancy vehicle (HOV) lanes for vans and carpools. Timed freeway entrances, which regulate the addition of cars to the freeway, are also common. Houston has an extensive network of freeway cameras linked to a transit control center to monitor and study traffic. One characteristic of Houston's freeways (and Texas freeways in general) are its frontage roads (which locals call "feeders"). Alongside most freeways are two to four lanes in each direction parallel to the freeway permitting easy access to individual city streets. Frontage roads provide access to the freeway from businesses alongside, such as gas stations and retail stores. New landscaping projects and a longstanding ban on new billboards are ways Houston has tried to control the potential side effects of convenience.
Houston has a hub-and-spoke freeway structure with multiple loops. The innermost is Interstate 610, forming approximately a 10 mile diameter loop around downtown. The roughly square "Loop-610" is quartered into "North Loop," "South Loop," "West Loop," and "East Loop." The roads of Beltway 8 and their freeway core, the Sam Houston Tollway, are the next loop, at a diameter of roughly 25 miles. A proposed highway project, State Highway 99 (The Grand Parkway), would form a third loop outside of Houston, though some sections of this project have been controversial. As of 2007, the completed portion of State Highway 99 runs from just north of Interstate 10, west of Houston, to U.S. Highway 59 in Sugar Land, southwest of Houston, and was completed in 1994. The next portion to be constructed is from the current terminus at U.S. Highway 59 to State Highway 288 in Brazoria County.
The Metropolitan Transit Authority of Harris County, Texas, or METRO, provides public transportation in the form of buses, trolleys, and lift vans.
METRO began running light rail service (METRORail) on January 1, 2004. Currently the track runs approximately 8 miles (13 km) from Downtown Houston to the Texas Medical Center and Reliant Park. METRO operates an extensive park-and-ride bus system to serve many of Houston's outlying suburban areas. Most of the park-and-ride buses run in barrier-separated high-occupancy-vehicle (HOV) lanes that provide direct service from park-and-ride parking lots to major employment destinations. Prior to the opening of METRORail, Houston was the largest city in the United States without a rail transit system.
Following a successful referendum held locally in 2003, METRO is currently in the beginning design phases of a 10-year expansion plan to add five more sections to connect to the current rail system. An 8.3 mile (13.4 km) expansion has been approved to run the service from the Uptown District (the Galleria area) through Texas Southern University, ending at the University of Houston campus.
Houston is served by two commercial airports—the largest of which is the George Bush Intercontinental Airport (IAH). The airport is the 7th-busiest in the United States for total passengers, and 16th busiest worldwide. Houston is the headquarters of Continental Airlines, Bush Intercontinental is Continental's largest hub, with more than 750 daily departures (more than 250 of which are Continental flights).
Bush Intercontinental currently ranks second in the United States for non-stop domestic and international service (221 destinations), trailing only Atlanta Hartsfield with 250 destinations. The United States Department of Transportation has also recently named Bush Intercontinental one of the top ten fastest growing airports in the United States.
The second-largest commercial airport in Houston is the William P. Hobby Airport (named Houston International Airport until 1967). The airport operates primarily small to medium-haul flights and is the only airport in Houston served by Southwest Airlines and JetBlue Airways.
The third-largest airport and former U.S. Air Force base, Ellington Airport (formerly Ellington Field), is primarily used for government and private aircraft. At one point, Continental Express operated flights across the city to Bush Intercontinental primarily for residents of southeast Houston and Galveston County. Passenger flights ended on September 7, 2004.
The Federal Aviation Administration and the state of Texas selected the Houston Airport System, which manages Bush, Hobby, and Ellington, as Airport of the Year for 2005, largely because of its multi-year, $3.1 billion airport improvement program for both major airports in Houston.
The following publicly-owned airports are in the Houston area:
The following privately-owned airports for public use are in the Houston area:
The Houston Air Route Traffic Control Center stands on the George Bush Intercontinental Airport grounds.
Amtrak, the national rail passenger system, provides service to Houston via the Sunset Limited (Los Angeles–New Orleans), which stops at the Houston Station on the north side of the Downtown area. The station saw 10,855 boardings and alightings in FY 2006.
Greyhound Lines operates services from five train stations:
In addition, Greyhound operates services from two stops :
Greyhound also operates services to stops within the Greater Houston area, including:
El Expreso Bus Company  operates services to a station in Houston adjacent to the Greyhound Station.
Tornado Bus Company operates services to two stations in Houston , with one along Airline Drive and one along Harrisburg.
In the 1990s various bus companies began operations in the East End, serving Mexico and other parts of the United States from East End terminals.
VivaAerobus, a Mexican airline, operated a bus shuttle between Austin-Bergstrom International Airport South Terminal and the Omnibus Mexicanos Bus Terminal in eastern Houston for VivaAerobus passengers on flights going to and from Cancun and Monterrey. On May 16, 2009, VivaAerobus stated it would cease passenger operations at Austin-Bergstrom International Airport on May 31, 2009. The airline blamed the pullout in part on the outbreak of the swine flu, which caused an unprecedented decrease in demand for service.
Texas Department of Transportation statistics said that in an eight county area including Houston, between 2003 and 2008, around 100 pedestrians died and 1,175 were injured in accidents every year. Mark Seegers, a spokesperson for Harris County commissioner Sylvia Garcia, said in 2009 that the county does not build sidewalks since it does not allow automobiles, the predominate form of transportation in the Houston area, to go from place to place. Robin Holzer, a transportation advocate with the Citizens' Transportation Coalition, criticized the emphasis on automobiles, saying "The people on foot and bike are trying to go to the same schools and restaurants and shops as people in cars are going to."
In 2005 the Houston-Galveston Area Council identified several communities in Harris County considered to be among the most hazardous to pedestrians. Many of them, including Greenspoint and Gulfton, are located outside of the 610 Loop. In 2009 the lobby group Transportation for America said that the Houston area was the eighth most dangerous area for pedestrians in 2007-2008.