Interstate 37

I-37 Texas
History
North End
South End
Interstate 37 north at the four-level interchange with IH 410 (Connally Loop) and U.S. 281 in south San Antono. Photo taken 09/29/07.

Overview

Interstate 37 links San Antonio with Corpus Christi and the Gulf Coast in South Texas. IH 37 provides connectivity to the Rio Grande Valley with U.S. 281 / IH 69C and U.S. 77 / IH 69E.  The freeway is also one of the only limited-access hurricane evacuation routes from the South Texas coastline inland towards San Antonio and Austin. Like IH 45, IH 37 located entirely within the Lone Star State.

Parallel U.S. Routes

IH 37 combines with U.S. 281 south from the McAllister Freeway and IH 35 at Downtown San Antonio to IH 410 at the Stinson Airport Vicinity in southeast San Antonio. U.S. 281 shifts westward along IH 410 to parallel 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 combines with IH 37 to IH 69E at Calallen in Corpus Christi.

Route Information

  • North End – San Antonio, TX

  • South End – Corpus Christi, TX

  • Branches – 0

  • Mileage – 143.00

  • Cities – Corpus Christi, Mathis

  • Junctions

Source: December 31, 2018 Interstate Route Log and Finders List

Interstate 37 was 44% complete in 1972

IH 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.

Interstate 37 & U.S. 281 north ahead of FM 541 near Liveoak Creek in Atascosa County. Photo taken 09/29/07.

Harbor Bridge

IH 37/US 181/SH 286 interchange schematic

The U.S. 181 Harbor Bridge Replacement Project, an $899 million span constructed 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 interchange joining IH 37 with the Crosstown Expressway (SH 286). The exchange will be rebuilt into 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 was the elimination of the Staples Street overpass above Interstate 37 to the east of the Crosstown Expressway. An at-grade intersection between the two was proposed in place of the crossing. This effort was meant to make the Downtown area more pedestrian friendly.1 It would have also shortened IH 37 by at least 0.6 miles. Work on the Harbor Bridge Replacement Project runs through April 2021.2

History

IH 37 was added to the original Interstate system in October 1957. It was included within the Texas Interstate Highway System by the State Highway Commission in 1962 with 142 miles.3

The proposed section of IH 37 north of Downtown San Antonio to IH 410 was 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 neighborhoods and other sensitive areas, the route was changed to avoid these features. This resulted into the number of S-curves along the freeway between IH 35 and IH 410. In 1973, the freeway was resurrected as a project to be built without federal funds as a new alignment for U.S. 281. Construction ensued through the mid-1970s, and the Walter McAllister Expressway (U.S. 281) opened to traffic on February 7, 1978.4 The systems interchange providing direct connection ramps between U.S. 281 and IH 410 did not begin construction until 2006. It was completed in June 2008.

Highway Guides

North End – San Antonio, Texas

I-37 US 281 North at I-35

IH 37/US 281 north at IH 35 - San Antonio, TX

Traveling between the Alamodome and the Henry B. Gonzalez Convention Center, IH 37/U.S. 281 north reach the final mainline off-ramp (Exit 141) for Commerce Street to Downtown San Antonio. Photo taken 09/29/07.

IH 37/US 281 north at IH 35 - San Antonio, TX

IH 37 wraps around the east side of Downtown San Antonio along a viaduct system to the systems interchange (Exits 142A/B) with IH 35. Photo taken 09/29/07.

IH 37/US 281 north at IH 35 - San Antonio, TX

Exit 142A departs next for IH 35 heading east to IH 410 and north to Austin and Dallas/Fort-Worth. Photo taken 09/29/07.

IH 37/US 281 north at IH 35 - San Antonio, TX

U.S. 281 extends the freeway from IH 37 north eight miles to San Antonio International Airport (SAT) at IH 410 and 14 miles to SL 1604 (C.W. Anderson Loop). Photo taken 09/29/07.

IH 37/US 281 north at IH 35 - San Antonio, TX

Left Exit 142B joins IH 35 south around the north side of Downtown San Antonio. IH 35 combines with IH 10 west of the central business district, while IH 10 leads northwest to Kerrville and Junction. Photo taken by Justin Cozart (08/31/08).

US 281 South at I-35 I-37

US 281 south at IH 35/37 - San Antonio, TX

U.S. 281 (McAllister Freeway) emerges from Brackenridge Park along an elevated roadway leading directly onto IH 37 at IH 35. Photo taken 08/03/19.

US 281 south at IH 35/37 - San Antonio, TX

Unnumbered ramps depart from U.S. 281 south for IH 35 south between Tobin Hill and Downtown San Antonio and IH 35 north between Government Hill and Digonowity Hill. Photo taken 08/03/19.

US 281 south at IH 35/37 - San Antonio, TX

IH 37 begins along U.S. 281 south at the exit ramp for IH 35 north to Kirby, Windcrest and Austin. Photo taken 08/03/19.

I-35 South at I-37 US 281

IH 35 south at IH 37/US 281 - San Antonio, TX

Exit 159A departs IH 35 south at the Walters Street overpass, 1.25 miles ahead of IH 37 south and U.S. 281 (McAllister Freeway). Photo taken 08/03/19.

IH 35 south at IH 37/US 281 - San Antonio, TX

Broadway and Alamo Street parallel IH 37/U.S. 281 within the vicinity of the exchange with IH 35. Broadway Street is the former alignment of U.S. 81 and SL 368 south of Alamo Heights. Photo taken 08/03/19.

IH 35 south at IH 37/US 281 - San Antonio, TX

Exit 158B separates from IH 35 south to IH 37/U.S. 281 south as both freeways encircle Downtown San Antonio. U.S. 281 travels 61 miles north from Exit 158A to Johnson City in Blanco County. Photo taken 08/03/19.

IH 35 south at IH 37/US 281 - San Antonio, TX

Exit 158B separates from IH 35 south to IH 37/U.S. 281 south as both freeways encircle Downtown San Antonio. U.S. 281 travels 61 miles north from Exit 158A to Johnson City in Blanco County. Photo taken 08/03/19.

I-35 North at I-37 US 281

IH 35 north at IH 37/US 281 - San Antonio, TX

Like IH 10 heading northwest to IH 410, IH 35 separates into upper and lower levels. The lower level constitutes a four-lane grade level freeway while a system of three-lane viaducts carry the upper level to IH 37/U.S. 281. Photo taken 08/04/19.

IH 35 north at IH 37/US 281 - San Antonio, TX

The upper level of IH 35 provides an express route to IH 37, while the lower level has local access to the adjacent street grid. Photo taken by Chris Patriarca (06/24/03).

IH 35 north at IH 37/US 281 - San Antonio, TX

The lower level lanes emerge just ahead of the four-level interchange (Exit 158) with IH 37 south and U.S. 281. Photo taken 08/04/19.

IH 35 north at IH 37/US 281 - San Antonio, TX

Exit 158 carries traffic to both IH 37/U.S. 281 south to Corpus Christi and the Rio Grande Valley and U.S. 281 (McCallister Freeway) north to SAT Airport. The IH 35 mainline continues east with three through lanes. Photo taken 08/04/19.

IH 35 north at IH 37/US 281 - San Antonio, TX

Exit 158 partitions into a local ramp for Broadway Street (old SL 368), which threads through the exchange at grade level along the historical route of U.S. 81. IH 37 and U.S. 281 overlap nine miles south to IH 410. Photo taken 08/04/19.

I-37 North End Throwback

IH 35 south at IH 37/US 281 - 2002

1.25 miles east of IH 37/U.S. 281 on IH 35 south at Walters Street, prior to an expansion project that added a lane to each direction. Photo taken 12/31/02.

IH 35 south at IH 37/US 281 - 2002

The New Braunfels Avenue off-ramp was relocated eastward to depart ahead of Frank Street as part of eventual IH 35 widening. The freeway proceeds west 0.75 miles to Exit 158B for IH 37 south to The Alamo and Downtown. Photo taken 12/31/02.

IH 35 south at IH 37/US 281 - 2002

Changes made to Exit 158B by 2016 restriped the off-ramp to just one lane for IH 37/U.S. 281 south to Corpus Christi. Photo taken 12/31/02.

IH 35 south at IH 37/US 281 - 2002

Two lanes were allocated for IH 37/U.S. 281 southbound from IH 35 south until 2016. IH 37 straddles eastern reaches of Downtown to the Alamodome. Photo taken 12/30/02.

South End – Corpus Christi, Texas

I-37 South at

IH 37 south at Buffalo St - Corpus Christi, TX

Heading east from the Crosstown Expressway (SH 286) south, back to back ramps depart from IH 37 south for Buffalo Street (Exit 1A) and U.S. 181 & SH 35 north to the Harbor Bridge. The new alignment for U.S. 181 will tie into a rebuilt cloverstack interchange with SH 286 here as part of the U.S. 181 Harbor Bridge Replacement Project. Photo taken 08/03/19.

IH 37 south at US 181 - Corpus Christi, TX

All ramps associated with the directional T interchange joining IH 37 and U.S. 181 & SH 35 north will be demolished. Broadway Street will be redesigned as a six-lane boulevard in place of the Harbor Bridge approach. Photo taken 08/03/19.

IH 37 south at US 181 - Corpus Christi, TX

IH 37 south extends east from the U.S. 181 flyover with two lanes for another quarter mile to Mesquite Street. Photo taken 09/29/07.

IH 37 south at US 181 - Corpus Christi, TX

Ramps from U.S. 181 & SH 35 south partition above the ending freeway for Broadway Street south and Twigg Street east to Shoreline Boulevard and the Corpus Christi waterfront. A right in right out (RIRO) intersection will replace this exchange between IH 37 and Broadway Street. Photo taken 08/03/19.

IH 37 south at Mesquite St - Corpus Christi, TX

Interstate 37 ends as a four-lane boulevard extending three blocks east from Mesquite Street to North Shoreline Boulevard and Corpus Christi Bay. Photo taken 08/03/19.

I-37 North at

IH 37 north at US 181 - Corpus Christi, TX

IH 37 stems west from Shoreline Boulevard as a landscaped boulevard three blocks to Mesquite Street. The freeway commences at the separation with the northbound on-ramp for U.S. 181/SH 35 to the Harbor Bridge and Portland. Photo taken 08/03/19.

IH 37 north at US 181 - Corpus Christi, TX

Flyovers join IH 37, U.S. 181 and SH 35 at Broadway Street. This exchange will demolished and IH 37 redesigned westward to the Crosstown Expressway as part of the Harbor Bridge Replacement Project through 2021. Photo taken 08/03/19.

IH 37 north at SH 286 - Corpus Christi, TX

The initial stretch of IH 37 north travels below grade between Downtown Corpus Christi and Martin Luther King Drive. Ramps join the freeway from U.S. 181 south and Padre Street as the freeway progresses west a quarter mile to SH 286 (Crosstown Expressway) south. The forthcoming exchange with SH 286 will be redesigned to accommodate the new Harbor Bridge approach. Photo taken 08/03/19.

I-37 South End Throwback

IH 37 south at US 181 - 2007

IH 37 south at the Buffalo Street off-ramp prior to Harbor Bridge Replacement Project. Photo taken 09/29/07.

SH 286 (Crosstown Expwy) north at IH 37 - 2000

SH 286 ends at the ramp split for IH 37 north to San Antonio and south to U.S. 181 (Harbor Bridge) and Shoreline Boulevard. With the new Harbor Bridge approach tying into this exchange from the north, all ramps here will be replaced as part of an interchange redesign. Photo taken by Jeff Royston (12/00).

IH 37 south at US 181 - 2000

Former button copy sign posted ahead of the U.S. 181 & SH 35 northbound off-ramp from IH 37 south. The Harbor Bridge carries both routes across Corpus Christi Channel to North Beach, where the Texas State Aquarium and the U.S.S. Lexington are located. SH 35 branches northeast from U.S. 181 in ten miles en route to Aransas Pass and Rockport. Photo taken by Jeff Royston (12/00).

IH 37 south at US 181 - 2000

Milepost zero preceded the flyover for U.S. 181 & SH 35 north from IH 37 south. The assembly was removed in 2016. Also ending here are U.S. 181 and SH 35. Historically U.S. 181 ran three blocks to the east along Water Street. Photo taken by Jeff Royston (12/00).

IH 37 south at US 181 - 2000

Non reflectorized signs directed traffic to U.S. 181 & SH 35 north to Portland and to the Interstate 37 boulevard east to Shoreline Boulevard and Bayfront Plaza, the previous name of the American Bank Center convention center and arena. Photo taken by Mike Wiley (09/00).

Shorline Blvd north at IH 37 - 2001

Trailblazers for IH 37, U.S. 181 and SH 35 north were formerly posted at the intersection of Shoreline Boulevard north with the Interstate Highway 37 boulevard extending west to the freeway. The IH 37 end point is a rare example where an Interstate, U.S., and State Highway all conclude at the same location. Photo taken by Jeff Royston (12/01).

US 181 south at IH 37 - 2000

U.S. 181 and SH 35 southbound conclude as traffic separates into ramps for the Corpus Christi Port Area to the northwest, IH 37 north to the Crosstown Expressway and Broadway Street south into Downtown. Photo taken by Mike Wiley (09/00).

Sources:

  1. “Harbor Bridge open house to show possible bridge modifications.” Corpus Christi Caller Times, June 23, 2016.
  2. “Groundbreaking ceremony held for Corpus Christi Harbor Bridge.” Rio Grande Guardian (TX), August 9, 2016.
  3. 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. http://tti.tamu.edu/interstate_anniversary/white_paper/
  4. 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. http://tti.tamu.edu/interstate_anniversary/white_paper/

Page updated August 12, 2019.