SR-57 Lambert Road Interchange Improvements

Approximately $99.8 Million in improvements will be made to provide additional capacity and improve the overall operational performance of the Lambert Road interchange and enable future construction of the SR-57 Northbound Truck Climbing Lane between Lambert Road and the Orange and Los Angeles County line.

What It Involves

  • Reconfiguring of ramps including construction of a loop on-ramp at the south-east quadrant.
  • Modify the northbound and southbound ramps.
  • Adding 0.4 miles of auxiliary lanes on southbound mainlines.
  • Widen Lambert Road and also lower the profile to provide 15-foot standard vertical clearance for the Lambert Road under-crossing.
  • Widening the northbound Lambert Road under-crossing bridge to accommodate the future truck-climbing lane project.


SR- 57 is a major interregional goods movement corridor that provides vital access between the counties of Orange, Los Angeles, Riverside and San Bernardino. Caltrans, in partnership with the City of Brea, will be making improvements on SR-57 at Lambert Road to relieve congestion, improve the operational performance of the interchange, accommodate future freight traffic increases, and provide safe mobility for all.

Currently, the interchange experiences heavy congestion during both the AM and PM peak periods stemming from conflicting traffic movements and inadequate signal queue capacity. Traffic counts indicate truck volumes of 12% during peak hour, and 17% during mid-day hours.

The proposed improvements will relieve current congestion and better accommodate anticipated future freight traffic increases, improve operational performance of the interchange; minimize delay and potential safety hazards for this segment of the roadway.

How does this work affect you?

Closures and Detours

Construction consists of improvements to the SR-57 northbound and southbound on and off-ramps, and to Lambert Road between State College Boulevard and Pointe Drive. While the work is performed, alternate lanes, off-ramps and on-ramps along SR-57 will be closed during non-peak hours. Signs will be posted to notify drivers of closures. 

When will construction take place? 

Construction is expected to begin in July 2019 and is expected to be completed in Fall 2023. 

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Contact the Project Team

For questions, please contact Sheilah Fortenberry, Public Information Officer, by email ( or at (949) 969-5055.