SH 21 Super 2 Widening and Rehabilitation

There were few opportunities to pass slower-moving vehicles on this rural, two-lane, high-traffic volume stretch of SH 21 between Crockett and Madisonville, Texas. To address the problem, TxDOT Lufkin District hired BGE to develop designs to widen, rehabilitate and add “Super 2” passing lanes to 7.8 miles of the highway. TxDOT’s goals were to improve safety and driver satisfaction without the cost and right-of-way impacts of a more traditional expansion to four lanes.

BGE’s comprehensive design included: rehabilitation of 7.8 miles of SH 21 to include wider shoulders; Super 2 passing lanes, left-turn deceleration lanes at intersecting farm to market highways; extension or replacement of cross drainage structures; safety treatment of fixed objects; and replacement of signage and pavement markings from the Trinity River at the Madison County line to FM 1280 in Austonio, Texas.

The project presented several challenges due to TxDOT’s requirements, including keeping the highway open to thru traffic during construction, maintaining continuous access for adjacent businesses and landowners, and ensuring the passing lanes were sufficient in length given the many curves, hills and limited right-of-way to expand. BGE developed a series of constraint maps, schematic plots and construction sequencing concepts to analyze potential solutions and communicate options. These proactive measures allowed TxDOT to fully understand all options and select a preferred alternative early in the final design process.

BGE prepared the final design package for the selected alternative and worked cooperatively with TxDOT throughout the design process. This approach helped keep the project on schedule, under budget and achieved the client’s goals for the project.