The project is being constructed in three segments, with construction beginning in April 2025 for Segment 1 - SR- 91/Lakeview Avenue Interchange. To maintain the safety of the traveling public and construction crews, slow down and stay alert while traveling through the Project area.

The SR- 91 Improvement Project, scheduled to break ground soon, will improve 5.6 miles of SR- 91 through Anaheim, Fullerton, Orange, Yorba Linda and Placentia. The project will improve mobility throughout the corridor, reduce weaving and merging between ramps, and improve on- and off-ramps, sidewalks and bike lanes at the Glassell Street, Tustin ...

ORANGE – Local, state and federal officials gathered today to commemorate the launch of the SR- 91 Improvement Project, a significant effort aimed at improving mobility, enhancing safety and overall traffic flow along one of Orange County’s busiest transportation corridors.

A two-year closure of the eastbound SR- 91 loop on-ramp from southbound Lakeview Avenue has begun and will support vital construction activities that are essential to modernizing the corridor.

Route 91 Construction Detour, Mission Viejo Effective Friday, July 11, 2025, until Friday, July 18, 2025, the buses on Route 91 will be on detour in the City of Mission Viejo due to construction.

SR- 91 (La Palma Avenue to SR-55) Will add one eastbound general purpose lane (~2.7 miles) in the eastbound direction and replace two overcrossing bridges from La Palma Avenue to SR-55.

The Orange County Transportation Authority (OCTA), in partnership with the California Department of Transportation (Caltrans), is improving State Route 91 (SR- 91) from State Route 57 (SR-57) to State Route 55 (SR-55).

Each year, OCTA and the Riverside County Transportation Commission update the SR- 91 Implementation Plan to ensure that projects are carefully coordinated to benefit drivers while minimizing construction impacts to commuters and the surrounding communities.

Click here to see May 11, 2025 Service Change Highlights Major routes & Connections Local Fixed Routes (Routes 1 to 99) Community Routes

Segment 1 Improvements Realign the westbound (WB) SR- 91 on-ramp at Lakeview Avenue interchange Add a new on-ramp from Lakeview Avenue connecting directly to SR-55 Separate the WB SR- 91 and southbound SR-55 traffic Reconstruct the Lakeview bridge Construction began in April 2025 and is anticipated to be completed in late 2027