• DTS.USA
    5.320
    -0.013
    -0.2%
  • NTI.USA
    2.800
    0.000
    0%
  • NTID.USA
    2.760
    -0.100
    -3.5%
  • NTIDL.USA
    1.940
    -0.100
    -4.9%
  • OTRI.USA
    6.190
    0.010
    0.2%
  • OTVI.USA
    12,391.500
    -166.900
    -1.3%
  • DTS.USA
    5.320
    -0.013
    -0.2%
  • NTI.USA
    2.800
    0.000
    0%
  • NTID.USA
    2.760
    -0.100
    -3.5%
  • NTIDL.USA
    1.940
    -0.100
    -4.9%
  • OTRI.USA
    6.190
    0.010
    0.2%
  • OTVI.USA
    12,391.500
    -166.900
    -1.3%
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FreightWaves Classics/Infrastructure: I-37 is a critical hurricane evacuation route

Like Interstate 2 (I-2), I-27 and I-45, I-37 is an intrastate interstate highway that runs entirely within Texas. Its total length is 143 miles.

San Antonio and Corpus Christi (and the Texas Gulf Coast) are linked by I-37. The highway also provides connectivity to the Rio Grande Valley via U.S. 281/I-69C and U.S. 77/I-69E. In addition, I-37 has a public safety role – it is one of the few limited-access hurricane evacuation routes from the Texas coastline inland toward San Antonio and Austin. 

The highway begins in Corpus Christi at US 181 and SH 35 and heads north to San Antonio, where it ends at I-35. 

A 1971 view of the freeway and interchange at I-35 under construction. (Photo: TxDOT/Texas Highway Man)
A 1971 view of the freeway and interchange at I-35 under construction. (Photo: TxDOT/Texas Highway Man)

History

Before I-37 was built, the primary route between Corpus Christi and San Antonio was Texas State Highway (SH) 9 from Corpus Christi to Three Rivers and US 281 from Three Rivers to San Antonio. 

I-37 was added to the original interstate highway system (IHS) plan in October 1957. The Texas State Highway Commission added it to the Texas Interstate Highway System in 1962. Construction of I-37 began in the urban areas of Corpus Christi and San Antonio in the early 1960s; however, I-37’s rural segments were not completed until the 1980s.

The first sections of the interstate were completed in Corpus Christi; the highway’s first section (1.2 miles in length) was finished in 1963. By 1968, the freeway had been completed  westward to Callicoatte Road. The I-37 bridge over the Nueces River was built in 1933 for US 77 (future I-69E) when it was first routed through Corpus Christi. The northbound bridge was newer; it had been built in 1958 when US 77 (future I-69E) was widened to four lanes.

Construction in San Antonio also began in the 1960s and was completed in 1972. The last section of the highway finished in San Antonio was the stack interchange at I-35 (which was also known as the San Antonio “Downtown Mixer”). When the interchange was finished, the city had a complete freeway loop around its central business district. (The loop also included portions of I-10 and I-35).  

Highway construction in rural areas

As noted above, the rural sections of I-37 were completed later than those in the urban areas. Construction in Corpus Christi and Nueces County continued north over the Nueces River and then into San Patrico County. SH 9 had been the primary road in this area; it became a frontage road after I-37 was built because many of the bridges along its length in this area were built in the 1930s at the same time SH 9 was constructed. Construction continued on the unfinished sections of I-37 throughout the 1970s. In 1981, I-37 was completed when the interchange at SH 72 and other bridges in the Pleasanton area were finished.

Conclusion

While I-37 is not a very long highway, it links two key Texas population centers. More importantly, though, is its role as an evacuation route during hurricanes.

The route of I-37, from Corpus Christi northwestward to San Antonio. (Image: ithighway.com)
The route of I-37, from Corpus Christi northwestward to San Antonio. (Image: ithighway.com)

Scott Mall

Scott Mall serves as Managing Editor of FreightWaves Classics. He writes articles for the website, edits the SONAR Daily Watch series, marketing material for FreightWaves and a variety of FreightWaves special projects. Mall’s career spans 45 years in public relations, marketing and communications for Fortune 500 corporations, international non-profits, public relations agencies and government agencies.