Interstate 37 is the freeway connection between San Antonio and Corpus Christi, in south-central Texas. As Corpus Christi is situated on the Gulf Coast southeast of San Antonio, the overall angle of Interstate 37 is northwest-southeast. The northwestern end in San Antonio is at a four-way interchange with Interstate 35; the freeway continues north beyond the Interstate 37 designation as US Route 281. The southeastern end in Corpus Christi is the downtown interchange that also features the southeastern end of US Route 181. Since its angle is more north-south than east-west, an odd number was a suitable choice for Interstate 37's designation.
My photo of an Interstate 37 marker comes from the northernmost at-grade intersection along US Route 181, on the southeast side of San Antonio, Texas. US Route 181's northern end is just after a turn to the right at the intersection in this photograph, and it's a point where it merges with Interstate 37 northbound. That's why the "TO" marker is appropriately placed here. The signage here faces mainly east. This photo was taken as part of the detour west to Texas, which occurred during the first Gulf Coast trip of October 2014. A lot of Interstates have a bestie US Route that follows alongside it; US Route 181 is Interstate 37's "bestie", following alongside it to the north and with endpoints in the same two cities. Back to the nationwide main page. Back to the home page.