Burns & McDonnell was selected to prepare plans, specifications and estimates to improve and expand a 2.4-mile portion of U.S. 75, a major artery between Dallas and the bustling northern suburbs in Collin County.
Demands on surface transportation infrastructure are steadily building as the Dallas-Fort Worth metro area grows by leaps and bounds.
The U.S. 75 corridor is a major artery between Dallas and the bustling northern suburbs in Collin County, one of the fastest-growing counties in the nation. Recognizing the dire need to expand this four-lane freeway, the Texas Department of Transportation (TxDOT) has engaged in 10 miles and $932.5 million of expansion projects between the cities of McKinney and Melissa, primarily funded with revenues from the nearby Sam Rayburn Tollway.
"The corridor is very congested and needs additional capacity," says Tony Kimmey, Burns & McDonnell regional transportation manager in Dallas. "It's a U.S. highway, but it serves this portion of our region as an interstate in every way except official designation."
Burns & McDonnell was selected to prepare plans, specifications and estimates to improve and expand a 2.4-mile portion of U.S. 75 between Bloomdale Road and Telephone Road in McKinney. The $70 million project includes expanding the highway from four lanes to eight and creating a continuous frontage-road network by reconstructing and raising the existing roadways above the 100-year flood plains of Honey Creek and the East Fork of the Trinity River. The project, slated for completion in 2015, includes 12 bridges.
"The biggest challenge was completing the work against a tight schedule," Kimmey says. "The project team had less than 11 months to finish the design work, which was completed on time and under budget."
The team also needed to coordinate with major reconstruction projects to the north and south and develop construction and traffic sequencing that matched schedules with these projects.
During the development of construction documents, the Burns & McDonnell team developed several modifications to the schematic plans that saved approximately $7 million, or 10 percent of the total construction cost. Working with TxDOT and the city of McKinney, the team analyzed traffic data and determined the number of frontage road lanes could be reduced from three to two in each direction while still providing a 30-year Level-of-Service B or better, saving about $6 million in construction costs.
"Another way we reduced construction costs was by shifting main-lane traffic onto the frontage roads during construction," says Tony Schmitt, associate structural engineer at Burns & McDonnell. "This approach not only saved approximately $1 million, but also improved safety by reducing the number of main-lane traffic shifts needed to construct the project."