Today the antiquated Mixmaster is gone—completely overhauled and replaced with the Dallas Horseshoe, a $798 million interchange that substantially improves the flow of traffic crossing the Trinity River along Interstate 30 and Interstate 35 to enter or exit the city’s downtown.
“Almost everybody that drives through Dallas uses this interchange, and for many people, it can be several times a day,” said Brown, who served as principal-in-charge for WSP USA on the project. “Those drivers are now experiencing significantly faster travel times.”
The original intersection, built in the late 1950s, was deteriorating and ill-equipped to handle the estimated 450,000 to 500,000 vehicles that pass through on a normal weekday.
“The left-lane exits at the interchanges and its odd geometry created a lot of weaving in and out of the lanes,” Brown said. “Now there is less weaving, less congestion, and the roadway is much safer for motorists.”
As the lead engineer, WSP was responsible for designing all of the roadways, bridges, river crossings, retaining walls, drainage, geotechnical engineering, and maintenance of traffic planning. The firm was teamed with Pegasus Link Constructors, a joint venture of Fluor Enterprises and Balfour Beatty, for the design-build contract to create the Dallas Horseshoe on behalf of the Texas Department of Transportation (TxDOT).
“The Pegasus Link team created an innovative maintenance of traffic plan that provided efficient working areas throughout construction that kept the traffic moving and minimized the impact on drivers using the interchange,” Brown said. “It was extremely important to TxDOT that road closures were limited, and our phased approach made sure that lanes were never shut down, other than intermittent overnight closures for demolition and bridge work.”
Design on the Horseshoe began in 2013, and construction began in January 2014. The Horseshoe was substantially completed on schedule in April.