Interstate 45 (I-45) is a major Interstate Highway located entirely within the U.S. state of Texas. While most primary Interstate routes which have numbers ending in "5" are cross-country north–south routes, I-45 is comparatively short, with the entire route located within Texas. Additionally, it has the shortest length of all the primary Interstates divisible by 5. It connects the cities of Dallas and Houston, continuing southeast from Houston to Galveston over the Galveston Causeway to the Gulf of Mexico.
I-45 replaced U.S. Highway 75 (US 75) over its entire length, although portions of US 75 remained parallel to I-45 until its elimination south of Downtown Dallas in 1987. At the south end of I-45, State Highway 87 (SH 87, formerly part of US 75) continues into downtown Galveston. The north end is at I-30 in Downtown Dallas, where US 75 used the Good-Latimer Expressway. A short continuation, known by traffic reporters as the I-45 overhead, signed as part of US 75 and also part of unsigned I-345, continues north to the merge with the current end of US 75. Traffic can use Spur 366 (better known locally as the Woodall Rodgers Freeway) to connect to I-35E at the north end of I-345.
The portion of I-45 between Downtown and Galveston is known to Houston residents as the Gulf Freeway. The short elevated section of I-45, which forms the southern boundary of Downtown, is known as the Pierce Elevated after the surface street next to which the freeway runs, while north of I-10 it is known as the North Freeway. I-45 and I-345 in the Dallas area, north of the interchanges with I-20 and SH 310 (old US 75), is the Julius Schepps Freeway. The Gulf Freeway and North Freeway both include reversible high-occupancy vehicle lane (HOV lanes) for busses and other HOVs to and from Downtown.
The freeway is the subject of ongoing controversy and federal investigation due to a proposed expansion project in Harris County, which would displace hundreds of people from their homes and worsen air quality. The local authorities have opposed the expansion project, while the Texas Department of Transportation (TxDOT) supports expansion, and negotiations are pending. The project's estimated cost is at least $9.7 billion and is expected to take at least two decades to complete.
Route description In addition to the official control cities of Galveston, Houston, and Dallas, I-45 serves a number of other communities, including Texas City, La Marque, League City, Spring, The Woodlands, Conroe, Willis, Huntsville, Madisonville, Centerville, Buffalo, Fairfield, Corsicana, and Ennis.
US 190 joins I-45 for from Huntsville to Madisonville. US 287 joins I-45 for from Corsicana to Ennis. US 287 signs are only posted (with I-45) from the northern end of Business I-45-F (Bus. I-45-F) in Corsicana to the Ellis County line.
I-45 gained notoriety during Hurricane Rita in 2005. Thousands of Houston area evacuees jammed the roadway trying to leave. As a result, the freeway became a parking lot. Gas stations ran dry and hundreds of people's cars simply ran empty, their occupants having to spend the night along the shoulder. Four-hour drives suddenly became 24-hour drives. Even though TxDOT started contraflow lane reversal at Farm to Market Road 1488 (FM 1488), it did not alleviate the traffic jam deep into the city, as that starting point was even north of The Woodlands, which is close to Conroe, the northern terminus of Greater Houston.
At just , I-45 is the shortest of the primary Interstates (ending in 0 or 5) and the only primary Interstate to be entirely inside of one state.
Gulf Freeway The stretch of I-45 connecting Galveston with Houston is known as the Gulf Freeway. It was the first freeway built in Texas—opened in stages beginning on October 1, 1948, up to a full completion to Galveston in 1952, as part of US 75. At the north (Houston) end, it connects to the North Freeway via the short Pierce Elevated, completed in 1967. The section north of the curve near SH 3/Monroe Road in southeastern Houston was built on the right-of-way of the former Galveston–Houston Electric Railway, which entered downtown on Pierce Street.
After several interchanges, I-45 crosses the Galveston Causeway and passes Tiki Island. Old US 75 south of this junction was upgraded on the spot.
The Gulf Freeway generally parallels SH 3 (old US 75) about to the west, bypassing La Marque, Dickinson, and South Houston. It includes interchanges with several other freeways: FM 1764 (Emmett F. Lowry Expressway), State Highway NASA Road 1 (NASA Road 1), and the Sam Houston Tollway (Beltway 8), meeting the north end of SH 3 in southeastern Houston. (This part of SH 3—on Winkler Drive and Monroe Road—is not part of old US 75.) A center reversible HOV lane begins just south of the Sam Houston Tollway.
In Houston, I-45 meets I-610 and SH 35 at a complicated interchange. At the merge with Spur 5, a short freeway spur to the University of Houston, elevated collector–distributor roads (also part of Spur 5) begin. The collector–distributor roads and the HOV lane end at Emancipation Avenue, the original end of the Gulf Freeway. Just past Emancipation Avenue is an interchange with I-69/US 59 (Eastex and Southwest freeways) and SH 288 (South Freeway), after which I-45 technically becomes the North Freeway as it runs along the northwest half of the block between Pierce Street and Gray Street as the Pierce Elevated.
The reversible HOV lane begins in Downtown at the intersection of St. Joseph Parkway and Emancipation Avenue, with easy access inbound to St. Joseph Parkway and outbound from Pierce Street. It runs down the median of the Gulf Freeway, mostly at the same level as the mainlanes. Ramps are provided for access to and from the following roads: Eastwood Transit Center (full access) I-610 north frontage road (full access) Monroe Road and Monroe Park & Ride (full access) Fuqua Park & Ride and South Point Park & Ride (full access) Frontage roads north of Dixie Farm Road (FM 1959) (toward Downtown, with a ramp stub for continuation)
The abandoned marshy land between Harris and Galveston through which the I-45 runs became known as the Texas Killing Fields because over 30 dead bodies have been found in the area.
North Freeway The I-45 North Freeway HOV begins in downtown Houston near the University of Houston–Downtown, with easy access inbound on Milam Street and outbound on Travis Street. Ramps and entrances are provided for access from the following roads. All are fully accessible. I-10/US 90 westbound exit and entrance only Quitman Street Airline Drive (to Crosstimbers Road) North Shepherd (to North Shepherd Park & Ride) FM 525 (Aldine-Bender Road) Kuykendahl Park & Ride FM 1960 (to Spring Park & Ride) The HOV ends approximately north of the FM 1960 (Cypress Creek Parkway) exit and becomes a diamond white line at grade separated HOV north to just before exit 84 Loop 336 on the south side of Conroe. This provides constant HOV access with one lane on the northbound side and one lane on the southbound side with periodic dotted lines for access at major exits.
Julius Schepps Freeway The stretch of I-45 along the Julius Schepps Freeway in Dallas, from the Trinity River to Downtown Dallas up to and including I-345, is elevated above the surrounding areas for most of its length. As such, when ice storms hit the Dallas area (usually on average one to two times per year), the freeway is shut down, and traffic is diverted to SH 310 and US 175, which parallel I-45.
History In the initial assignment of state highways in 1917, the Dallas–Fort Worth metroplex and Greater Houston were connected by a branch of SH 2 (Meridian Highway), which ran via Waco and Bryan and continued on to Galveston. The more direct route followed by I-45 was not initially part of the system between Richland and Huntsville; this cutoff was added by 1919 as SH 32, and US 75 was assigned to the alignment in 1926. Prior to the coming of the Interstate Highway System in the late 1950s, the only improvements to US 75 in Texas beyond building a two-lane paved roadway were in the Houston and Dallas areas. The highways in and near these cities, however, included some of the first freeways in the state: the Gulf Freeway (Houston) and the Central Expressway (Dallas).
Gulf Freeway (Houston to Galveston)
The Galveston–Houston Electric Railway began operating an interurban between those cities on December 5, 1911, and last ran on October 31, 1936, though the Houston Electric Company, operator of Houston's city transit system, continued to run trains on the portion between Downtown and Park Place. A proposal for a "superhighway" between the cities was first made in 1930, and Houston Mayor Oscar F. Holcombe began to work toward it later that decade. He announced an agreement with the Houston Electric Company on April 12, 1940, through which the company could convert its four remaining lines to busses in exchange for the right-of-way used by the Park Place line. This line was last used on June 9, 1940, the last day of streetcar service in Houston; the replacement is still operated by the Houston Metro as the 40 along Telephone Road.
Before the new highway was built, US 75 followed Galveston Road (now mostly SH 3), Broadway Street, and Harrisburg Boulevard into Downtown. SH 225 carried traffic from La Porte along La Porte Road to US 75 in Harrisburg, and SH 35 connected Alvin with Downtown along Telephone Road and Leeland Street. Plans made in October 1943, when the Texas Transportation Commission signed an agreement with Houston and Harris County, referred to the new bypass as a relocation of US 75. Drawings were released by the state on January 31, 1946, and included almost continuous frontage roads, broken only at railroad crossings. Although the freeway ended at Live Oak Street, a so-called "four-street distribution system" of four one-way streets, timed for , carried traffic to Main Street. Initially, the two southwestern streets—Pierce Street and Calhoun Avenue (now St. Joseph Parkway)—carried traffic toward the freeway, and the other two—Jefferson and Pease streets—carried exiting traffic; once the freeway was completed far enough to allow US 75 to be marked along it, Pease and Pierce streets carried that highway to Fannin Street.