Completed in April 2017, the Dallas Horseshoe is a $798 million interchange that substantially improves the flow of traffic entering and leaving the city.
The new interchange completely overhauled and replaced the Mixmaster, which had served the region since the late 1950s but was deteriorating and ill-equipped to handle the 450,000 to 500,000 vehicles that pass through on a normal weekday.
The Dallas Horseshoe included the construction of more than 73 lane miles of new roadway, 37 conventional bridges and more than 60 retaining walls.
WSP was the lead engineer, responsible for designing the roadways, bridges, river crossings, retaining walls, drainage, geotechnical engineering, and maintenance of traffic planning. The firm teamed with Pegasus Link Constructors, a joint venture of Fluor Enterprises and Balfour Beatty, for the design-build contract on behalf of the Texas Department of Transportation (TxDOT).
Thanks to TxDOT's decision to choose design-build delivery, WSP and Pegasus Link were able to make more than 70 geometric refinements to the plan during design and construction, ensuring they stayed on schedule while systematically building the roadways from the outside lanes inward, allowing motorists to continue using the old lanes until the new ones were ready.
“Both projects successfully dealt with extraordinary MOT [maintenance of traffic] issues,” Rattigan said. “The Horseshoe project included multiple sequencing issues and provided equal or improved mobility throughout construction. The Elizabeth River Project had to deal with both roadway traffic maintenance and permitting for waterway mobility which was collaboratively addressed with SKW.”