Texas Transportation Code - TRANSP § 644.202. Designation of Route

(a) A political subdivision of this state or a state agency may designate a route for the transportation of nonradioactive hazardous materials over a public road or highway in this state only if the Texas Department of Transportation approves the route.

(b) A municipality with a population of more than 1.3 million shall develop a route for commercial motor vehicles carrying hazardous materials on a road or highway in the municipality and submit the route to the Texas Department of Transportation for approval.  If the Texas Department of Transportation determines that the route complies with all applicable federal and state regulations regarding the transportation of hazardous materials, the Texas Department of Transportation shall approve the route and notify the municipality of the approved route.

(c) The Texas Transportation Commission may designate a route for the transportation of nonradioactive hazardous materials over any public road or highway in this state.  The designation may include a road or highway that is not a part of the state highway system only on the approval of the governing body of the political subdivision that maintains the road or highway.