The Texas Department of Transportation (TxDOT) put safety at the forefront when it built the Northaven Trail Bridge.
Located in Dallas, this S-curved pedestrian bridge spans across the busy eight-lane U.S. Route 75. Installed in a single night, the bridge links several bike and pedestrian trails to the highway, while also improving safety.
The site designated for the Northaven Trail Bridge has a unique geometry that required the bridge to be built at an angle across the eight mainlanes and four frontage road lanes of U.S. 75. The structure is the only known network tied arch bridge in the world with a doubly curved tie.
The bridge also has skewed ends, making it an incredibly complex structure not seen anywhere else, and for these reasons, it earned the No. 3 spot on this list.
“It’s surprising how much the final design adhered to some of the early sketches and modeling concepts developed from conversations with the city of Dallas and other stakeholders,” said Tom Kramer, HNTB project manager. “Often, an early concept and what is ultimately built are quite different. In this case, we developed a unique, initial concept and saw it all the way through.”
Prior to opening, the Northaven trail stopped where it met the west side of U.S. 75. To reach the Cottonwood Creek and White Rock Creek trails on the east side of the highway, pedestrians and bicyclists traveled through a poorly lit and muddy underpass.
This idea for this project dates back to the early 2000s, when former Dallas City Council Member Lee Kleinman proposed a trail bridge crossing U.S. 75. The original bridge concept was developed in 2017.
TxDOT formed the project team with Ragle, Inc. and Mammoet as the contractors and HNTB as the designers for the new bridge. The two-phase project began in 2021.
The project team purposely designed the bridge to be preassembled and transported to the final location because U.S. 75 is one of the busiest highways in Texas. Multiple design models were created during design and construction to ensure the move would be a success. It was placed overnight using Accelerated Bridge Construction (ABC) techniques.
The main span of the bridge has inclined circular arch ribs that reach a height of 500 feet at mid-span. The network cable arrangement reduces bending in the arch and deck, allowing both to be thin while still being resilient.
HNTB made sure the structure was a lightweight, redundant system that could be safely transported. The bridge deck, cables and arch were constructed as a single structure on timber shoring.
Moving the bridge took approximately 20 hours but required only 14 hours of full closures on the main lanes. U.S. 75 carries approximately 250,000 vehicles daily, so minimal impact to the traveling public was a hurdle the team had to overcome.
Traffic was diverted to the adjacent frontage road, leaving one lane of traffic open to drivers during the move.
The Northaven Trail Bridge opened late last year. Not only does the new structure increase safety in the region, but it also promotes multimodal transportation and community connectivity.
“TxDOT is proud to have delivered this signature project for the region,” said Nathan Petter, TxDOT Dallas County Area engineer. “The power of positive partnerships and collaborative spirit drives us to push the limit on what we can accomplish for our Texas roadways.”
This project brings significant environmental benefits to the region while providing a safe and accessible route for pedestrians and bicyclists. It encourages sustainable transportation alternatives, alleviating traffic congestion in the area.
Project: Northaven Trail Bridge
Location: Dallas, Texas
Owners: The Texas Department of Transportation
Designer: HNTB Corporation
Contractor: Ragle, Inc., Mammoet
Cost: $11 Million
Length: 201 Feet
