A stretch of the northbound Interstate 35 access road near New Laredo Highway on San Antonio's Southwest Side shut down Friday after hazmat crews were called to investigate a parked 18-wheeler emitting a strong, foul odor. Witnesses told authorities the truck appeared to be pulling a refrigerated trailer that may have been carrying beef, though officials have not confirmed what, if anything, was inside.
Hazmat crews from Lone Star Hazmat Response responded to the scene to assess the smell coming from the trailer, according to KSAT. The Texas Department of Transportation confirmed the northbound access road near New Laredo Highway was closed as crews worked the scene. Authorities have not determined how long the truck had been parked along the roadway or what exactly caused the odor.
What Investigators Still Don't Know
The unanswered questions are piling up faster than answers. It remains unclear who owns or was driving the 18-wheeler, whether the vehicle was intentionally left along the access road, or whether any hazardous material leaked onto the pavement. Those details matter under Texas law: a motor vehicle left unattended for more than 24 hours on a controlled-access highway right-of-way, or 48 hours on other state highway rights-of-way, can legally be classified as abandoned and subject to impoundment, per the Texas Transportation Code.
If the trailer's contents turn out to involve a hazardous or industrial waste spill above state thresholds, the responding contractor or responsible party would be required to notify the state's emergency hotline within 24 hours under Texas Commission on Environmental Quality rules outlined in 30 TAC Chapter 327, according to guidance published by Protect Environmental Services. Whether that kind of report gets filed in this case is one more thing left to be seen.
Why a Refrigerated Trailer Might Reek in August Heat
If the trailer really was carrying beef and its refrigeration unit failed, the timing could hardly be worse. San Antonio was forecast to hit 96°F on Friday with a heat index climbing above 101°F, according to AccuWeather, conditions that dramatically speed up organic decomposition inside an unpowered refrigerated unit. That kind of heat can turn a mechanical hiccup into a roadside stench emergency within hours.
Lone Star Hazmat Response, the contractor on scene, is headquartered in Tyler and runs 24/7 spill response centers across the state under contract with TxDOT for exactly this kind of roadside containment work, according to the company's own description of its operations. Notably, the firm filed an application with the Federal Motor Carrier Safety Administration on June 30 seeking an exemption from federal hours-of-service rules so its crews could safely drive home after emergency roadside responses, a request detailed in the Federal Register. That filing underscores how often the company's crews get called out to jobs like this one, sometimes with little notice and long hours to follow.
A Corridor Built for Freight, and Trouble
The stretch of I-35 where the truck was found sits along what TxDOT calls “The Main Street of Texas,” a 590-mile trade corridor that funnels commercial freight north from the U.S.-Mexico border at Laredo through San Antonio. That volume of freight traffic comes with risk: state records compiled by legal researchers at Webster Vicknair MacLeod show Texas leads the nation in large-truck traffic incidents, with 4,150 total traffic fatalities recorded across the state in 2024.
TxDOT has been gathering public feedback since April as part of its I-35 Texas Corridor Study, an ongoing effort to address traffic delays, road safety, and commercial freight congestion along the interstate, as reported by KSAT. The New Laredo Highway interchange in particular has a history of major commercial vehicle disruptions; a double 18-wheeler crash there in July 2024 forced a complete shutdown of the interstate's main travel lanes.
Not the First Rough Stretch for This Interstate
Friday's closure adds to a string of recent commercial-vehicle incidents that have rattled San Antonio's roadways. A San Antonio Fire Department engine collided with a delivery box truck on Marbach Road on the West Side in February, triggering a six-vehicle crash that hospitalized seven people. Hoodline also previously reported on a fatal I-35 SUV crash near O'Connor in early July that involved a stopped 18-wheeler and caused major lane closures.
For now, officials have offered no timeline for reopening the access road or determining the source of the odor. KSAT said it will update its report as more information becomes available.
