Section 2: History of the Texas Highway Trunk System

Initial Creation of the Texas Highway Trunk System

In response to a downturn in the Texas economy during the mid-1980’s and in anticipation of new federal legislation, TxDOT developed a long-range highway plan in 1988 called the Texas Highway Trunk System. The main objective of the Trunk System was to identify rural highway segments, based on specified criteria that are to be upgraded to a four-lane divided cross section to encourage economic development of rural areas. The first Trunk System, consisting of 10,500 miles, was completed and approved in 1990. In 1998, the Trunk System was revisited and refined to accommodate for urban area expansion, as well as to consider other segments to be added to the network. This resulted in the addition of approximately 500 miles to the system. The system was last amended in 2001 to add approximately 475 miles.
A route had to meet one or more of the following criteria to be considered as part of the Trunk System:
  • maximize the use of existing four-lane divided roadways,
  • minimize circuitous or indirect routing,
  • connect with principal roadways from adjacent states (AADT ≥ 1,000),
  • connect with principal deep-water ports with channel depths of 40 feet or more,
  • connect with principal Mexican ports of entry (AADT ≥ 5,000),
  • serve significant military or other national security installations,
  • serve tourism and/or recreational areas,
  • comprise major truck routes (1,850 trucks per day), or
  • be located within 25 miles or less of cities of 10,000 population or greater.

Previous updates to the Texas Highway Trunk System

May 28, 1998 – Minute Order 107484 -
 TxDOT updated the Trunk System network and proposed the addition of eight new routes consisting of 506 miles. As part of the revision, it was proposed that the Trunk System upgrades should be completed as full corridors to provide increased mobility over long distances. Forty-five corridors became known as Priority (subsequently renamed Phase 1) Corridors. Furthermore, the State was divided into five regions (northwest, northeast, west, southeast, and south) to ensure geographical equity of investments. Corridors not recognized as “priorities” were designated as “Other Trunk Highways”.
August 31, 2000 – Minute Order 108286 –
 The TAC was amended concerning the Trunk System to include changes to the selection criteria. Closing gaps in the system and providing system connectivity were added as criteria.
June 28, 2001 – Minute Order 108541 -
 Following the public hearing in January 2001, the Trunk System was amended to add certain routes and to delete one route.
2018 –
 The Trunk System was reevaluated to determine if segments still met the criteria and if any segments should be added or deleted from the network. The reevaluation was presented to the Commission several times for discussion. No action was taken on the reevaluation. Staff will continue discussions with Administration and the Commission on next steps.

Phase 1 Corridors

Phase 1 Corridors were identified by the Texas Transportation Commission in 1998 as priority corridors for allocation of construction funds for expanding two-lane Trunk System highways to four-lane divided highways. Specific criteria used to select Phase 1 corridors included:
  • Truck and total traffic volumes,
  • Gap or percentage of the corridor that is 4-lane highway,
  • Mexico Connector, and
  • Bypass of metro areas.