The Texas Department of Transportation (TxDOT, pronounced "tex-dot") is a government agency in the U.S. state of Texas. Though the public face of the agency is generally associated with the construction and maintenance of the state's immense highway system, the agency is also responsible for overseeing aviation, rail, and public transportation systems in the state. At one time, TxDOT also administered vehicle registration; but this function transferred to the Texas Department of Motor Vehicles, a newly created state agency which began operations in November 2009.