Interstate 45

North End
South End


An intrastate route, Interstate 45 joins Houston and the Texas Gulf Coast with the Dallas/Ft. Worth Metroplex along the former route of U.S. 75. Beginning on Galveston Island, IH 45 replaced U.S. 75 along the Gulf Freeway, a pre-Interstate era route constructed between Galveston and Houston. Angling northwest, the freeway passes by NASA’s Johnson Space Center toward South Houston, Park Place and Downtown Houston. Within central Houston, the route briefly runs side by side with Interstate 10 and U.S. 90. IH 45 ventures north from there to North Houston, Aldine, Spring and other northern Houston suburbs.

Beyond Conroe, Interstate 45 transitions to a rural freeway through Sam Houston National Forest. Exiting the forest, the freeway turns more west from Huntsville to Madisonville while remaining rural to Coriscana. Increasingly busy, IH 45 proceeds from there to Ennis, Ferris, Wilmer and Downtown Dallas.

The northern terminus of Interstate 45 is at the southern terminus of Interstate 345, which is signed as the southernmost portion of U.S. 75. An exit numbering anomaly occurs here. The exit numbers of I-45 continue northward along U.S. 75 and the hidden I-345 to the Woodall Rogers Freeway (Texas Spur 366), approximately 1.4 miles north of Interstate 30. Traveling southbound on U.S. 75, the Woodall Rogers Freeway is signed as Exit 1A. Just beyond the ramp to Spur 366, U.S. 75 encounters Exit 285 to Ross Avenue. The IH 30 junction is signed as Exit 284A.1

Future Plans

A section in the ISTEA (1991) legislation indicates that U.S. 69 will become part of the Interstate highway system once it is up to Interstate standards; the most logical designation would be Interstate 45, assuming that the highway connects to U.S. 75 in southern Oklahoma. This is taken from ISTEA Section 1074, Designation of United States Route 69, which states, “Notwithstanding any other provision of law, upon the request of the Oklahoma State highway agency, the Secretary shall designate the portion of United States Route 69 from the Oklahoma-Texas State line to Checotah in the State of Oklahoma as a part of the Interstate System pursuant to section 139 of title 23, United States Code.” A current plan is to construct a new segment of the Oklahoma Turnpike along the U.S. 69 corridor to bring it to corridor standards.

Route Information

  • North End – Dallas, TX

  • South End – Galveston, TX

  • Branch Routes – 1

  • Mileage – 284.91

  • Cities – Galveston, Texas City, Houston, Huntsville, Corsicana, Ennis, Dallas

  • JunctionsI-610 I-10 I-69 I-20 I-30 I-345

Source: December 31, 2017 Interstate Route Log and Finders List

Southeastern Texas – 1967 Texas Official Highway Map

Interstate 45 ran north from Galveston to Madisonville by 1964. The route was extended north to Buffalo in 1971.

Interstate 45 originally took the South Central Expressway (later renamed to the S.M. Wright Freeway) toward Downtown Dallas. The freeway between Grand Avenue to Texas 310 was completed on August 15, 1956. It was bypassed by a new alignment of IH 45 in 1976. The portion of freeway north of SH 310 is slated for removal by 2020.4


In Texas, Interstate 45 was an original Interstate Highway, and it was approved by the Texas State Highway Commission in 1962 with 286 miles.2 IH 45 was the recipient of the first Interstate Highway contract to be let in Texas; it was authorized in 1956 to complete a section in Navarro County near Corsicana.2 However, the first section of Interstate 45 to be built was the U.S. 75 / Gulf Freeway segment, which opened in September 1948. After being upgraded to Interstate standards, the Gulf Freeway was signed as IH 45 in 1971. The North Freeway segment of Interstate 45 in Houston started construction in December 1959 and was completed (north to Spring) by February 1963.

Additional sections of Interstate 45 opened in stages: during the 1960s, sections opened included the stretch from Conroe to Madisonville, the section from Madisonville to Centerville, and the bypass around Corsicana. During the early 1970s, the section from Centerville to Buffalo opened. The final gap of rural freeway was opened on October 13, 1971, between Fairfield and Streetman in Freestone County along a 12-mile section. Remaining sections opened in the mid to late 1970s included the relocated Central Expressway in Dallas and the stretch of IH 45 connecting Buffalo, Richland and Fairfield.3

Highway Guides

North End I-30 I-345 US 75 – Dallas, Texas

Perspective from Interstate 45 north
Interstate 45 north ends opposite U.S. 75, which extends northward along the Central Expressway toward McKinney and Sherman. Exit 284A departs next for IH 30 to Fort Worth and Texarkana. Photo taken 10/19/03.
Exit 284A separates from IH 45 north as IH 345 and U.S. 75 north begin. The Central Expressway forms the east leg of an inner belt freeway network encircling Downtown Dallas. IH 30, IH 35E and SS 366 make up the other three legs. Photo taken 10/19/03.
Interstate 30 crosses the city of Dallas west to Grand Prairie and Arlington and east to Mesquite and Lake Ray Hubbard. IH 30 connects with IH 35E (Stemmons Freeway) nearby at the Mixmaster Interchange. Photo taken 10/19/03.
Perspective from Interstate 345 & U.S. 75 south
IH 345 and U.S. 75 end opposite IH 45, which extends the freeway southeast along the Trinity River to the city of Hutchins. Interstate 45 replaced U.S. 75 south from Downtown Dallas to Galveston Island. Photo taken 09/05/09.
Two lanes lower from the elevated roadway for IH 30 east to Mesquite and west to Arlington and Fort Worth. Photo taken 09/05/09.
Perspective from Interstate 30 west
Interstate 30 winds southwest through the Deep Ellum community on the approach to IH 45 south and U.S. 75 (IH 345) north. Photo taken by Chris Patriarca (06/20/03).
Exit 47B separates from IH 30 westbound with two lanes for IH 45 south and unsigned IH 345 & U.S. 75 (Central Expressway) north. Exit 47A follows from the left side to an older section of the Central Expressway (since renamed Cesar Chavez Boulevard) and U.S. 75. Photo taken by Chris Patriarca (06/20/03).
Perspective from Interstate 30 east
Leaving the Mix Master Interchange with IH 35E (Stemmons Freeway), IH 30 advances east 1.25 miles to IH 45 south and IH 345/U.S. 75 (Central Expressway) north. Photo taken 10/19/03.
Collector distributor roads accompany both sides of Interstate 30 from the Mix Master Interchange to Cesar Chavez Boulevard. The next departure point from the mainline is for the Central Expressway north and IH 45 south. Photo taken 10/19/03.
A slip ramp takes motorists on the adjacent c/d roadway onto IH 30 east at the upcoming Griffin and Ervay Street overpasses. Just a quarter mile separates the ingress point with Exit 46, resulting in a weaving traffic pattern. Photo taken 10/19/03.
Two lanes separate from IH 30 east for the distributor roadway (Exit 46) to IH 45 south to Ennis, Corsicana and Houston and IH 345/U.S. 75 north to Plano, McKinney and Sherman. Photo taken 10/19/03.
Interstate 45 ends 285 miles south of the systems interchange with IH 30 in Galveston. Interstate 345 northbound accompanies U.S. 75 (Central Expressway) for just 1.40 miles to Spur 366 (Woodall Rogers Freeway). Photo taken 10/19/03.

South End SH 87 – Galveston, Texas

Perspective from Interstate 45 south
The final two interchanges of IH 45 south connect with 71st Street at Exit 1B and State Spur 342 (61st Street) at Exit 1A. Traffic interests to the Galveston beaches partition between 61st Street for the West beaches and SH 87 (Broadway Avenue) for the East beaches. Photo taken by Chris Patriarca (06/22/03).
Exit 1A departs for SS 342 southbound to Galveston International Airport – Scholes Field, accessible from Jones Drive via 61st Street. One half mile of Interstate 45 remains. Photo taken by Chris Patriarca (06/22/03).
Traffic from 61st Street north merges onto IH 45 south ahead of the signal with SH 87 (Broadway Avenue). SH 87 links Galveston Island with the Bolivar Peninsula and Port Bolivar via a auto ferry. The state highway is part of a longer coastal route that formerly traveled to High Island and Sabine Pass. Beach erosion however, washed away the roadway between High Island and Sabine Pass. Therefore motorists must travel northward via SH 124 to IH 10 and SH 73 to reach the eastern segment of SH 87. Photo taken by Chris Patriarca (06/22/03).
Perspective from Interstate 45 north
SH 87 (Broadway Avenue) transitions into IH 45 north just beyond the signal with 59th Street and an adjacent retail center. Exit 1A follows to SS 432 (61st Street), which leads to the Gulf of Mexico waterfront and Seawall Boulevard. The succeeding ramp (Exit 1C) connects with SH 275 (Harborside Drive), a road straddling the southern shoreline of Galveston Bay. Photo taken by Chris Patriarca (06/22/03).
This sign bridge precedes the split diamond interchange (Exit 1A) with Spur 342 (61st STreet). SS 342 in conjunction with FM 3005 provides a coastal route from Galveston southwestward to Jamaica Beach, Sea Isle, Surfside Beach and ultimately Freeport. Photo taken by Jeff Morrison (12/30/05).


  1. Michael R. Wilson, email: “I-45/I-345/US-75 in Dallas” August 11, 2003
  2. “From Anywhere to Everywhere: The Development of the Interstate Highway System in Texas.” by Penny Beaumont, Rhonda Brinkmann, David Ellis, Chris Pourteau, and Brandon V. Webb, Texas Transportation Institute, page 29 and 34.
  3. Celebrating the 50th Anniversary of the Eisenhower Interstate Highway System: Previous Interstate Facts of the Day by the Federal Highway Administration (FHWA).
  4. Chapter 6 Excerpt: US 175, S.M. Wright and C.F. Hawn Freeways, Dallas-Fort Worth Freeways, 2014 ebook.

Page updated September 27, 2018.