T.Y. Lin International Wins 2021 ACEC Engineering Excellence Honor Award for I-5 High-Occupancy Vehicle Improvement Project in Santa Ana, California

T.Y. Lin International (TYLI), a globally recognized full-service infrastructure consulting firm, announces that the Interstate 5 High-Occupancy Vehicle Improvement Project between State Route 55 and State Route 57 (I-5 HOV Improvement Project) in Santa Ana, California, has won a prestigious 2021 Honor Award in the American Council of Engineering Companies (ACEC) Engineering Excellence Awards (EEA) competition. The annual national competition recognizes engineering firms for projects that demonstrate an exceptional degree of innovation, complexity, achievement, and value.

TYLI served as Prime Design Consultant for the final design phase of the I-5 HOV Improvement Project, working closely with the Orange County Transportation Authority (OCTA), California Department of Transportation (Caltrans), and the City of Santa Ana. The firm excelled at proactively identifying potential issues and risks, allowing sufficient time to develop resolutions and partnering with stakeholders to reach consensus. By anticipating issues, TYLI was able to save on project costs while meeting budget and schedule requirements.

Opened to traffic three months early in August 2020, the $41.5 million I-5 HOV Improvement Project provides a significant benefit to the traveling public by repurposing the existing width of the I-5 freeway and adding a second HOV lane in each direction between SR 55 and SR 57. In total, the project added close to six lane miles of HOV lanes to a heavily congested portion of I-5, which will be traveled by 400,000 vehicles each day by 2035.

Challenges overcome included replacing the single-lane northbound and southbound HOV lanes with two southbound HOV lanes while realigning two northbound HOV lanes into an area previously used for northbound general-purpose lanes. Innovative solutions included constructing a retaining wall under the abutment of an existing railroad bridge to create the space needed to accommodate the northbound general-purpose lanes. TYLI's use of creative geometric designs to "thread" the four HOV lanes under bridges eliminated the need for widening in the southbound direction.

Another challenge concerned the Main Street HOV drop-ramp bridge structure demolition, which required full freeway closures. TYLI collaborated with OCTA and Caltrans design and construction staff to present demolition options. The demolition was ultimately completed during a single weekend freeway closure.

"T.Y. Lin International developed solutions for the complex challenges of this project in partnership with the entire project team," said Project Manager Karen Chapman, P.E., TYLI Vice President, Transportation Services Manager and Orange County Branch Manager. "This spirit of collaboration had a direct impact on the success of this project. The innovative solutions we developed can also be considered on future projects, redefining how road and highway projects like this are typically approached."

TYLI joined its project partners in accepting the award at the 2021 Virtual ACEC Engineer Excellence Awards Gala on June 17, 2021.