Cost-effective and innovative project upgraded eight county road bridges
OKLAHOMA CITY, Okla. (Feb. 21, 2025) – HNTB, a leading infrastructure solutions firm, has been honored with the ACEC Oklahoma Grand Conceptor Award for its innovative engineering work on the I-35 Haunched Slab Bridge Raises project in Kay County, Oklahoma. This prestigious award recognizes exceptional contributions to the engineering industry.
HNTB partnered with the Oklahoma Department of Transportation (ODOT) to raise eight county road bridges over I-35 to meet updated vertical clearance requirements to accommodate a 10” pavement overlay under the bridges. HNTB developed a unique solution to elevate continuous haunched slab bridges, a bridge type not typically considered for raising. This approach balanced cost savings, safety and efficient construction methods, providing a model for future infrastructure rehabilitation projects.
“We are honored to receive the ACEC Oklahoma Grand Conceptor Award for the I-35 Haunched Slab Bridge Raises project,” said Marcus Geist, Oklahoma practice leader and associate vice president at HNTB. “This project leveraged innovative engineering solutions that prioritize safety, efficiency and cost-effectiveness. We are proud to have partnered with ODOT to deliver a project that will benefit the traveling public for years to come.”
The project achieved significant cost savings by opting to raise the 1950s bridges rather than rebuilding them and reconstructing the I-35 pavement below. Additionally, safety was a paramount consideration in the project. By attaching falsework to the existing piers, the team maintained horizontal clearance and eliminated the need for bulky falsework towers, allowing traffic to flow safely under the bridges. This innovative approach enhanced safety for both contractors and motorists.
“The success of the I-35 Haunched Slab Bridge Raises project is a testament to the vision provided by ODOT and the expertise utilized by HNTB to deliver this vision,” said Natalie McCombs, senior technical advisor and associate fellow at HNTB. “We are thrilled to be recognized by ACEC Oklahoma and look forward to continuing our work on impactful infrastructure projects.”
The ACEC Oklahoma Grand Conceptor Award was presented during the ACEC Oklahoma 2025 EEA Ceremony in Tulsa, Oklahoma on February 6, 2025.