Texas Truck Bans & Hazmat Routes

Where Texas keeps trucks out

No cars-only parkways in Texas. Your metro traps are the tunnel and the low rail bridge. Houston's Washburn Tunnel under the Ship Channel bans flammable and hazardous loads and limits LP gas to small DOT cylinders, with about 13 feet of lane clearance (HCTRA). Houston's truck-route program, adopted in 2023, pushes rigs of 26,000 pounds or more onto designated routes, $500 a violation. Placarded loads stay on the Interstates and posted hazmat routes (49 CFR 397). A car GPS knows none of it.

Key restrictions

• Washburn Tunnel (Galena Park to Pasadena): about 13 ft lane clearance, no flammable/hazmat, LP gas limited to small DOT cylinders
• Houston truck-route program: rigs 26,000 lb GVW or more (or 3+ axles) must stay on designated routes; $500 fine
• Low rail underpasses in Houston and Dallas trap box trucks; run your true loaded height
• No parkway commercial bans; watch posted city truck routes and weight-limited residential streets

• Parkway / road ban: No cars-only parkways. Trucks get kept off certain local streets by city truck-route ordinances (Houston, Dallas, San Antonio, Austin), not parkway law.
• Hazmat: Houston's Washburn Tunnel under the Ship Channel bars flammable and hazardous loads and caps LP gas at two 7.5-gallon or one 10-gallon DOT cylinder (valve closed in the tunnel), with LP-gas fuel systems prohibited; lane clearance runs about 13 feet (18 feet center lane). Elsewhere placarded loads default to the Interstates and follow any posted city hazmat route under 49 CFR 397.
• Through-truck routes: Houston's truck-route program (Code Ch. 33, adopted November 2023) sorts a network for commercial vehicles of 26,000 lb or more, or three-plus axles: through routes, local routes, and no-through-truck streets, $500 a violation. It launched as a pilot in the Settegast/East Houston area. Dallas, San Antonio and Austin post their own truck routes and weight-limited streets. Off the network you keep reasonable access to a local stop.
• Fine: Houston truck-route violation up to $500. Driving oversize or over-height without a TxDMV permit is a misdemeanor with escalating fines; a tunnel or bridge strike is on you.

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