SR 241/Oso Parkway Bridge and Interchange Improvements

SR 241/Oso Parkway Bridge and Interchange Improvements

Orange County, California
United States
SR 241 Oso Parkway

TYLin provided final design services for the Oso Parkway Bridge and Interchange Improvements project at SR 241 in Orange County, California.

Completed on an extremely accelerated schedule for Transportation Corridor Agencies (TCA), the Oso Parkway Bridge and Interchange Improvements project provides vehicular traffic with a direct connection between Los Patrones Parkway and SR 241, improving safety, connectivity, and traffic flow. Before this project, drivers were forced to access SR 241 or Los Patrones Parkway by exiting via an off-ramp, waiting at a signalized intersection, and using an on-ramp to access either roadway.

The new Oso Parkway Bridge provides three lanes in each direction and dedicated bike lanes and pedestrian sidewalks to enhance user safety. A new sidewalk was also constructed on the south side of Oso Parkway for students to access Tesoro High School.

To ensure compatibility with the concurrent projects and compliance with California Department of Transportation (Caltrans) standards, TYLin designed the ramps on the south side of the interchange. Roadway improvements included asphalt pavement, a storm drain, curb and gutter, sidewalks, Americans with Disabilities Act (ADA) upgrades, signing and striping, drainage improvements, and traffic signal modifications. New mainline toll gantries and associated infrastructure were also included in TYLin’s design.

Challenges included significant utility relocations due to the bridge construction and right-of-way (ROW) processing requirements. Drainage design also had to meet Orange County and Caltrans standards based on various ownerships and ROWs within the project limits.

Project Highlights:

  • The project included bridge construction, roadway design, freeway infrastructure, a Transportation Management Plan, and California Environmental Quality Act (CEQA)/National Environmental Policy Act (NEPA) implementation.
  • TYLin ensured the bid package complied with Orange County requirements so that the County could advertise, award, and administer the construction contract.
  • Staged construction included pedestrian detours to maintain an accessible travel path for students at the adjacent Tesoro High School during each stage of construction.
  • TYLin provided design support services to the County during construction as needed.


Roadway and Highway Project of the Year, 2021
American Society of Civil Engineers (ASCE), Los Angeles Section
Outstanding Bridge Project, 2020
ASCE, Orange County Branch

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