The method the Texas Department of Transportation uses to decide on future road projects is based on dozens of factors, according to its manual for development, a state and federally mandated series of documents that are continually updated.
The process of obtaining data is the same, but handled differently by the Austin, Dallas-Fort Worth and Houston metro areas. In Austin, TxDOT and the metropolitan planning organization compile the information.
The North Central Texas Council of Governments works with TxDOT to produce the Dallas-Fort Worth Travel Model. The Houston-Galveston Area Council does the same modeling work with TxDOT for the Houston area.
In addition, traffic analysis zones, districts and sectors are formed by the metropolitan planning organizations throughout the state and TxDOT. There are 26 districts throughout the state with populations that exceed 200,000 that use data from studies, surveys and devices including automatic traffic recorders to update the plan for road development.
The collected data is then used to update the needs throughout the state based on the yearly growth.