SR-57 Pavement Replacement Project

Location and Limits

In Los Angeles County in Diamond Bar and City of Industry from Orange County line to Route 57/60 Separation

The Project

The SR-57 Pavement Replacement project spans 4.4 miles between the SR-60/SR-57 confluence and the Orange County line. State Route 57 is a major commute corridor that connects Orange County to Los Angeles County. This project will restore and replace damaged concrete slabs on all lanes and ramps within the project limit. Additional work includes upgrading the concrete median barrier, replacing Metal Beam Guardrails (MBGRs), sign structures and panels, upgrading AC dikes, Americans with Disabilities Act (ADA) curb ramps, replacing traffic loop detectors, and installing 14 permanent Treatment Best Management Practice (BMP) devices.


4.4 miles


These improvements will restore the facility and improve ride quality by rehabilitating the existing pavement with a pavement structure that will provide a service of 40 years for lane replacement and five to 10 years for slab replacement.


Summer 2020 through late 2023

Concerned Communities

Diamond Bar

Total Programmed Project Costs

$103.98 Million


Q: Will this project close the freeway at any time?

A: Some lanes may be closed in either direction or both directions simultaneously to facilitate a safe work zone for workers and motorists. At least one or two lanes in each direction will remain open for traffic while work is underway. For the latest road conditions, go to Caltrans Quickmap. All work is weather dependent and subject to change.

Q: What are the current closures for this project?

A: Current closures:

  • Southbound SR-57 High Occupancy Vehicle (HOV) lane
  • S Brea Canyon Road on-ramp

Q: Will this project be noisy at night?

A: Residents and businesses near project areas will experience noise from construction related activities. Loud noise may be experienced during the project's demolition phase. Noise will dissipate as construction progresses from each location. Caltrans will monitor noise levels during construction to minimize the impact to local neighborhoods. If you experience excessive noise or dust related to this construction project, please contact Caltrans.

Q: Will the speed limit be reduced in the construction zone?

A: California Highway Patrol (CHP) officers regularly patrol the area to enforce the 55 mile-an-hour speed limit. Motorists are encouraged to “Slow for the Cone Zone” and be “Work Zone Alert.” Traffic fines are also doubled in construction zones.

Q: When will the project start?

A: Summer 2020

Q: When is the project expected to be complete?

A: Spring 2023

Q: Can I receive news releases for this project?

A: Yes, please contact the Caltrans PIO below and you will be added to the project distribution list.

Contact Information

To receive email updates about this project, contact the Caltrans representative shown below.

Jeremiah Teves
Public Information Officer
Caltrans – District 7
Twitter @CaltransDist7