Interstate 37 or I -37 is an Interstate Highway in the United States, located entirely in the state of Texas. The highway forms a north-south route in the south of the state, connecting the coastal city of Corpus Christi with the major city of San Antonio. I-37 mostly runs through monotonous prairies. Interstate 37 is 230 kilometers long.
I-37 / I-69E at Robstown.
I-37 at Oakville.
I-37 at San Antonio.
The starting point of I-37 in San Antonio.
The highway begins in Corpus Christi, a large coastal city of 285,000 in southern Texas. The route starts in the center of this city, immediately with 2×3 lanes. After one kilometer, the interchange with SR-286 is the Crosstown Freeway, which leads to the southern suburbs of the city. There are a number of refineries along the highway, as this is a fairly important oil port. On the east side of the city, one crosses the SR-358, the city’s ring road. After this you leave the city, but you enter a large industrial area with mainly refineries. South of Odem, one intersects US 77, a major road that leads to the extreme south of the state, the area around McAllen, Harlingen, and Brownsville, which is another 250 miles to the south. A little further on there is the intersection with theUS 77 heading north to Victoria and Houston.
According to topschoolsintheusa, the highway then runs through a flat agricultural area, with little to no height differences. One passes a short distance from Lake Corpus Christi, a reservoir. Frontage Roads lie along I-37. At George West you cross the US 59, which runs from Houston and Victoria to Laredo, on the Mexican border. At Three Rivers, US 281 joins in from McAllen. This road is part of a well-developed OWN, with 2×2 lanes and few intersections. The US 281 is more or less double numbered with the I-37, but also has a number of parallel alternative routes, the so-called ALT 281. At Pleasanton the US 281 turns off again. One now enters the area of influence of San Antonio, with already a number of distant suburbs.
One crosses Interstate 410 on the southeast side of San Antonio, through a 4-level stack interchange. San Antonio is a large city with 1,297,000 inhabitants, and almost double that in the metropolitan area. Only in San Antonio does the road widen to 2×3 lanes, as this is not a very busy commuter route. San Antonio is quite densely built up, so there is quite a bit of traffic after every exit, and the highway already has 2×4 lanes for a few miles. Another 4-level stack interchange crosses Interstate 10, which comes from El Paso and heads toward Houston. I-37 runs east of downtown until it intersects with Interstate 35. This is where I-37 ends at US 281, which runs further north as a highway.
The highway in San Antonio is the Adams Freeway, named after a World War II veteran. The Interstate 37 number was also requested by the state of Illinois, in 1990, for the highway between Lincoln and Morton. This was rejected, and that route came to be called Interstate 155.
The first section of the highway was opened in Corpus Christi, a two-mile stretch that opened in 1963. The route in the Corpus Christi region was completed in 1968. At the same time, construction was underway in the San Antonio area. The route was completed in San Antonio in 1969 north of US 181. The rural section between Corpus Christi and San Antonio was opened mainly during the 1970s, although the last section was not opened until 1981 around Pleasanton.
In the mid to late 1980s, the dual numbering of I-37 with US 77 west of Corpus Christi was widened to 2×3 lanes. The interchanges with US 77 have also been reconstructed. Later, US 77 also became part of I-69E. In the mid-1990s, the section between SH 358 and I-69E west of Corpus Christi was widened to 2×3 lanes. In 2019, proceedings were initiated to widen a short section of I-37 near Corpus Christi from 2×3 to 2×4 lanes, between I-69E and US 77. The bridges over the Nueces River have also been replaced with higher and wider bridges. The interchange with US 77 towards Sinton has also been reconstructed. The work was carried out between 2021 and 2025.
The data below concerns intensities after the relevant exit.