Heads up, drivers: An interstate in San Antonio is partially shut down on Wednesday, July 8, after an 18-wheeler crashed in a road construction zone. 

The collision occurred on the southbound lanes of I-35 at around 6:23 a.m., and drivers are still feeling the delays nearly an hour later, according to the Texas Department of Transportation (TxDOT). All lanes between Judson Road (Exit 170) and O’Connor Road (Exit 169) are closed. Traffic is backed up to FM-1518 (Exit 174).

Commuters are being forced to exit to the frontage road, but they can re-enter the highway south of the crash. TxDOT officials are recommending the following alternate routes: Lookout Road, Nacogdoches Road/FM 2252, or Wurzbach Parkway.

Most cars in the area are at a complete stop. Those that are moving are traveling between 1 and 11 mph. The traffic monitoring site SigAlert states that delays could last up to two hours. There is no word on when the lanes will reopen or if anyone was injured in the crash.

Make sure to visit the MySA traffic page for the latest transportation news, including traffic delays and construction projects around San Antonio.

This is a developing story. Check back for updates.