I-37 San Antonio Construction: $40M Diamond Interchange

What happened

I-37 San Antonio construction is starting on the Southeast Side. TxDOT, the Texas Department of Transportation, is breaking ground on a $40 million project on Interstate 37. The work runs about 2 miles, from Southeast Military Drive (State Loop 13) to Loop 410.

The big piece is a new diverging diamond interchange at I-37 and Southeast Military Drive. It will be the second one in San Antonio. The first is at Loop 1604 and Blanco Road.

A diverging diamond works like this. As you cross the bridge, traffic moves to the opposite side of the road for a short stretch. That way, you can turn left without waiting for oncoming traffic to stop. It also cuts the number of spots where two vehicles can crash.

Here is what KSAT reported on Sept. 24:

• The project should be done in 2029.
• Most lane closures will happen at night, from 9 p.m. to 5 a.m. on weekdays.
• Some daytime and weekend closures may also happen to keep the job on schedule.
• State traffic models show up to 90% less travel time for drivers leaving southbound I-37 onto Southeast Military Drive.

TxDOT is working with the Alamo Area Metropolitan Planning Organization, the City of San Antonio and Brooks on the project.

What it means for owner-operators

This is a Texas story, but it matters to anyone who runs I-37 between San Antonio and Corpus Christi, or who uses Loop 410 on the Southeast Side. That includes a lot of drivers coming up from the Rio Grande Valley and the coast.

Night work is good news for day traffic. But if you drive at night, plan for lane closures on weekdays between 9 p.m. and 5 a.m. Work zones mean lower speeds, narrow lanes and sudden merges. That is where a lot of rear-end crashes happen.

The new interchange will feel strange the first few times. Traffic crosses to the "wrong" side for a moment. Follow the signs and lane lines, not your habit. Trucks need extra room on those curves, so slow down before you enter.

The work runs until 2029, so this is a long project. Closures can move from week to week.

What to do next

• Check DriveTexas.org or TxDOT alerts before you leave, especially for night runs through the Southeast Side.
• Add extra time on I-37 and Loop 410 while the job is going on.
• In the work zone, slow down, keep your following distance and watch for workers.
• Tell your drivers and dispatch about the night closures so loads and appointments are planned right.
• Keep your paperwork as ready as your route. New carriers can use our new entrant safety audit guide to get ready.

Need your USDOT, IFTA or IRP in order before your next run? Call TCZ Permits at 956-526-6727. Filings can come at no cost when you factor with us.