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Sam Rayburn Tollway (State Highway 121) Improvements (Section 15A)
Denton and Collin Counties, Texas
  • The improvements to Sam Rayburn Tollway in the Counties of Collin and Denton came out to be a $104 million project. 


  •  Bridgefarmer was responsible for the plans, specifications and estimate and environmental assessment documents as well other engineering services.


Bridgefarmer modified conceptual design and environmental assessment documents and provided engineering services for widening and reconstructing a 6.4 mile section of an existing four-lane divided highway to a six-lane divided freeway with auxiliary lanes, 26 on-off ramps and new three-lane one-way urban frontage roads in each direction. This project includes the design of five diamond interchanges, four bridges over the Burlington North Santa Fe (BNSF) Railroad and design of over 30 retaining walls. The project also included complex maintenance of traffic control plans.

New interchanges were included in this project at the following cross streets:

  • Standridge Drive (Lewisville and The Colony)
  • FM 423 Main Street (The Colony)
  • Paige Road/Plano Parkway (The Colony)
  • Morningstar Blvd (The Colony)
  • Spring Creek Parkway (Plano)
  • Legacy Blvd (Plano)

A bridge over the BNSF Railroad track was replaced to provide a consistent typical section and to attain clearance criteria with the railroad facilities. The Bridgefarmer team produced the new Railroad Agreement draft and processing for Texas Department of Transportation (TxDOT) and the BNSF.

This Bridgefarmer team role includes preparation of plans, specifications and estimate (PS&E) for bridges, retaining walls, roadway, pavement design, frontage road storm sewer systems, culverts, construction sequencing, traffic control plans, SW3P, ramp safety lighting, permanent highway signing, and pavement markings. Additionally Bridgefarmer provided representation at monthly public information meetings and produced its project web pages to disseminate secured updates to the involved agencies and general information to the community.  

Bridgefarmer took various steps in order to operate efficiently and save on cost. First, Bridgefarmer developed construction sequencing and traffic control plans that maximized new paving in the new ROW space available. Refining mainlane profile to save embankment cost was also required to reach project cost goals. Our team also revised schematics for improved access ramp lane geometry and U-Turn Lanes. Finally, Bridgefarmer introduced Sam Rayburn Tollway into monthly utility coordination meetings with the County and provided continuity with utility companies working the Sam Rayburn Tollway/Dallas North Tollway Interchange project.