Chapter 2: Texas Highway Trunk System

Section 1: Overview

Purpose of the Texas Highway Trunk System

The Texas Highway Trunk System (Trunk System) is a network of rural divided highways that complements and includes the rural portion of the Interstate Highway System. The minimal design criteria for this network specify that each highway should be at least a four-lane divided facility. The Trunk System serves as a principal connector for all Texas cities with over 20,000 population as well as major ports and points of entry to the state. The total mileage of the Trunk System, as stated in TxDOT Minute Order 910209, is limited to 11,500 miles.

Laws and Regulations regarding the Texas Highway Trunk System

Route selection criteria for the Trunk System are found in the Texas Administrative Code (TAC), Title 43, Chapter 16, Subchapter B, Section 16.56 ( ).

Texas Highway Trunk System Update Frequency

The 1990 commission minute order adopting the Trunk System included a provision that the Trunk System be reviewed every four years to determine if revisions are needed.
Updates to the Trunk System mileage automatically occur when urbanized areas expand as a result of the decennial Census, reducing the number of miles on the system.

Texas Highway Trunk System Location

The statewide planning map has a layer for the Trunk System. The statewide planning map is located at .