IH 635/LBJ Managed Lanes
Double the capacity for traffic mobility, but design “no higher and no wider.” Those were the orders Bridgefarmer & Associates, Inc. faced as the Lead Design Firm for the IH-635 / LBJ Managed Lanes Project in north Dallas. This meant that the proposed elevations within the LBJ corridor could be “no higher” than the highest existing elevation within the project limits, and the proposed improvements could be “no wider” than the existing right-of-way.
This $2.7 Billion project reconstructed the freeway’s eight existing general purpose lanes and added six new managed (tolled) depressed lanes below in an excavated trench section – a design alternative which saved project construction over $400M. At the time the project was awarded, the State’s budget was only a fraction of the projected construction cost. Funding for the project was met through partnering among many public and private agencies, and project delivery under a Public Private Partnership (PPP).
Bridgefarmer was the Lead Engineer and corridor concept creator for the entire project, and Engineer of Record for Segments 1 and 2A, which consisted of a 5-level interchange at IH-35E and IH-635, a
3-level interchange at IH-35E and Loop 12, roadway, bridges, drainage, retaining
walls, complex traffic control, ITS, signing, striping and illumination within the IH-35E
and IH-635 corridors. The entire project limits along IH-635 stretched from east of Luna Road to west of Coit Road near the Dallas High Five, and along IH-35E from Northwest Highway at Loop 12 to Valley View Lane– 17 miles in all. Bridgefarmer delivered 188 separate design packages for various elements including 45 bridges (beams totaling 66 miles in length); 14 miles of managed lanes; 5 miles of general purpose lanes; 481,000 sf of retaining walls; 44,000 lf of box culverts, and 56,000 lf of storm drain pipe.
Project Construction Cost: $4 Billion
Completion Date: 2015
Client: Texas Department of Transportation