Interstate 37 provides a link between San Antonio and Corpus Christi in South Texas. Like Interstate 45, IH 37 is entirely located within the Lone Star State. The freeway also provides part of through route to the Rio Grande Valley via connections with U.S. 281 / Interstate 69C and U.S. 77 / Interstate 69E. IH 37 is also one of the only limited-access routes available during a hurricane evacuation situation, being the main escape route from the South Texas coastline inland towards San Antonio and Austin.
Parallel U.S. Routes
Interstate 37 combines with U.S. 281 south from its independent freeway through north San Antonio to Downtown and Interstate 410 in southeast San Antonio. U.S. 281 shifts westward along IH 410 to its parallel alignment to IH 37 south to Leming and Pleasanton. The two come together again between Exits 103 and 72 near Three Rivers. U.S. 281 branches south from there toward Alice while the remainder of IH 37 mirrors the course of U.S. 181 southeast to Corpus Christi. U.S. 77 also briefly ties into Interstate 37 at Robstown and Interstate 69E.
North End – San Antonio, TX
South End – Corpus Christi, TX
Branches – 0
Mileage – 143.00
Cities – Corpus Christi, Mathis
- Junctions –
Source: December 31, 2017 Interstate Route Log and Finders List
Interstate 37 was completed from San Antonio south to FM 1303 (where Loop 1604 crosses IH 37 now) by 1972 and from Corpus Christi north to FM 534 at Swinney Switch.
The U.S. 181 Harbor Bridge Replacement Project, an $899 million span planned to replace the 1959-built bridge for U.S. 181 to the east, broke ground on August 8, 2016.1,2 Four Proposed Build Alternatives were considered as of July 2013. The Red Alternative was ultimately chosen. It ties in the new 538 foot tall cable-stayed bridge2 and alignment with the IH 37 interchange with the Crosstown Expressway (SH 286). Redesign of that exchange will replace the current design with a new directional T interchange with high speed flyovers between north-south U.S. 181 / SH 286 and IH 37 to the west. Connections with the IH 37 spur to the east will use the frontage roads in place of direct ramps.
An additional refinement considered for the bridge design is the elimination of the Staples Street overpass above Interstate 37 to the east of the Crosstown Expressway. An at-grade intersection between the two is proposed in place of the crossing. This effort is meant to make the Downtown area more pedestrian friendly.1 It would also in effect shorten Interstate 37 by at least 0.6 miles. Work on the Harbor Bridge Replacement Project runs through April 2021.2
Interstate 37 was added to the original Interstate system in October 1957. It was included within the Texas Interstate Highway System by the Texas State Highway Commission in 1962 with 142 miles.3
The proposed section of Interstate 37 north of Downtown San Antonio to Interstate 410 was first planned as the North Expressway, a route connecting Downtown with the airport. Original plans called for the freeway to travel a straight line north from Downtown. However, local opposition arose due to the potential local impacts of the freeway. A lawsuit by the San Antonio Conservation Society resulted in an injunction preventing construction of the freeway as an Interstate in 1967.
Opposition to the freeway project remained through the late 1960s and early 1970s. The struggle reached a national audience when the freeway was profiled in Helen Leavitt’s book Superhighway-Superhoax. With its proximity to or passage through parkland, a college campus, schools, residential areas and other sensitive areas, the route was changed to avoid these features. This helps explain the many curves of the freeway between Interstates 35 and 410. In 1973, the freeway was resurrected as a project to be built as U.S. 281 and without federal funds (and therefore not as part of IH 37). Construction ensued through the mid-1970s, and the Walter McAllister Expressway (U.S. 281) opened to traffic on February 7, 1978.4 The interchange offering direct connection ramps between U.S. 281 and Interstate 410 did not begin construction until 2006.
North End – San Antonio, Texas
South End – Corpus Christi, Texas
- “Harbor Bridge open house to show possible bridge modifications.” Corpus Christi Caller Times, June 23, 2016.
- “Groundbreaking ceremony held for Corpus Christi Harbor Bridge.” Rio Grande Guardian (TX), August 9, 2016.
- 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.
- 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 24.
Page updated August 30, 2017.