Construction Updates

Stay informed with updates

Sign up for our construction alerts, which will be sent regularly when construction starts, by filling out the Stay Informed form. If you have further questions, please feel free to contact our team and we will be happy to help. Previous weekly construction alerts are posted at the bottom of this page.

Lakeview Avenue Bridge Pile Driving Activities

Crews completed the first two portions of pile driving in the center median of the freeway and along westbound SR-91. Work in the final location, along the eastbound SR-91 off-ramp, is underway and will continue on weekdays through Friday, Oct. 17. Crews may be on the worksite as early as 6 a.m. and are anticipated to perform pile driving activities from 7 a.m. to 4 p.m.

While pile driving is a critical step in the construction process, it may also be noisy and cause some vibration.

What is Pile Driving?

Pile driving is a common construction method used to build a strong foundation of large structures, such as bridges. During this process, long steel beams, known as piles, are driven deep into the ground with the help of a powerful hammer mounted on a construction rig.

As of July 7, 2025, Eastbound SR-91 Loop On-Ramp is Closed for Approximately Two Years

Construction Closures & Detours

Closures and detours for the SR-91 Improvement Project

Segment 1, SR-91/Lakeview Avenue Interchange

Segment Improvements

Reconstruct Lakeview Avenue overcrossing to include standard lanes, shoulders and sidewalks in each direction
Realign westbound State Route 91 (SR-91) on-ramp at Lakeview interchange
Add new on-ramp from Lakeview connecting directly to SR-55
Separate westbound SR-91 and southbound SR-55 traffic

Segment 2, Between SR-55 and SR-57

Segment Improvements

Add new eastbound general purpose lane
Reconstruct Kramer Boulevard and Tustin Avenue overcrossings to include standard lanes, shoulders and sidewalks in each direction

Segment 3, SR-91/SR-57 Interchange

Segment Improvements

Improve westbound SR-91 to northbound and southbound SR-57 connectors Add an auxiliary lane from SR-57 to Raymond Avenue/East Street off-ramp
Reconstruct La Palma Avenue overcrossing to include standard lanes, shoulders and sidewalks in each direction
Add bypass ramp for northbound SR-57 Orangethorpe Avenue off-ramp prior to SR-91, eliminating the need to merge across multiple lanes at the interchange

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SR-91 Improvement Project

Construction alert

SR-91 Improvement Project Construction Alert

As of Oct. 3, 2025

Contact the SR-91 Community Outreach Team

If you have questions or would like to request information in other language, please contact the Outreach Team at (888) 280-7966 or email 91project@octa.net.

91improvements

91Project@octa.net

SR-91 (SR-57 to SR-55) Improvement Project