Chino Hills Fighting Caltrans on Widening Scenic Carbon Canyon Road for Truck Use

Hope for the Hills is a well-known group of Chino Hills residents who won a long and arduous battle against utility giant Southern California Edison back in 2013. I reported extensively and for several years on their courageous multi-year fight.

After several years of legal challenges, the California Public Utilities Commission issued a final decision in 2013 in the Tehachapi Renewable Transmission Project, which granted the City of Chino Hills its proposal to run new electrical transmission lines underground, rather than living with the 200 foot electrical towers SCE installed in their backyards and parks.

They’re back.

Hope for the Hills is now battling Caltrans to preserve the character and safety of Carbon Canyon Road/State Route 142, approximately 8.4 miles through the canyon from Chino Hills to Brea. It has long been a two-lane canyon route with safety, congestion, and truck-suitability issues due to topography.

Why would Caltrans want to widen a two-lane route now?

Residents told the Globe that an Amazon distribution center is going into Brea. The Globe asked if there aren’t any other routes for Amazon trucks?

Bob Goodwin with Hope for the Hills answered affirmatively that there are other routes: the 91 freeway to the South; the 57 freeway to the West; the 71 freeway to the East; and the 60 freeway to the North.

So why go after Carbon Canyon Road? It may be the shortest distance to San Bernardino County, Goodwin said, but unsuitable for semi-trucks.

However, he added that there is an old bridge from 1925 in the area, that have not been retrofitted since.

A 1989 Southern California Association of Governments (SCAG) report on Carbon Canyon Road, State Route 142, warned it should not be a designated commuter route, was unsafe for trucks, and warned of environmental constraints – and that was before Chino Hills was even a city (1991). The route was also deemed unsafe for trucks.

Residents, homeowners associations, and local officials have raised concerns about safety, evacuation, and especially fire risk, quality of life, property impacts, as well as the road’s character as a scenic residential route, rather than a truck corridor.

Caltrans has proposed widening the switchbacks, referred to as S-curves, on Carbon Canyon Road between Carriage Hills Lane and Azurite Drive, and residents say Caltrans has even talked about taking property by eminent domain.

This is a truck violating the no-trucks rule on Carbon Canyon Road switchbacks, from the Hope for the Hills Facebook page:

Feasibility evaluations for S-curve improvements date back several years; formal project initiation occurred around 2022–2023, with funding secured later and environmental work starting in early 2025.

According to the CEQA project overview of Carbon Canyon Road S-Curve Widening in Chino Hills proposes to widen the “S-curve” switchbacks.

The Caltrans Scope includes:

• Widening existing pavement on both sides of the curves to better accommodate truck turning movements.
• Constructing retaining walls (with some temporary construction easements).
• Replacing/upgrading culverts and drainage.
• Guardrail upgrades.
• Removing existing street lighting and adding new lighting for better visibility.

The project aims to improve safety and operations for larger vehicles, despite previous truck bans, Champion Newspapers reported recently. Estimated cost is about $13 million, listed in the 2026 State Highway Operation and Protection Program. Construction is targeted for summer 2028, with completion by late 2029.

Environmental Status

Caltrans’ Draft Initial Study with a proposed Mitigated Negative Declaration concluded “no significant environmental impacts.”

Chino Hills residents told the Globe that the Caltrans CEQA report claiming “no significant environmental impacts” is BS, especially with the 1989 Southern California Association of Governments report on Carbon Canyon Road, State Route 142, that it should not be a designated commuter route, was unsafe for trucks, and warned of environmental constraints.

Caltrans scheduled a Zoom meeting with residents, rather than an in-person meeting. “As a community with strong roots to Carbon Canyon for decades, we’re appalled that Caltrans chose to spring this project on us with little to no notice,” Bob Goodwin with Hope for the Hills said. “When pressed for a meeting, Caltrans chose to schedule a public hearing via Zoom. Why don’t they want to face our community?”

Goodwin told the Globe that this issue goes back over 10 years when the group met to discuss the canyon highway with their Councilman and Caltrans. Two feasibility studies were done and submitted to Caltrans, which resulted in the agency banning large trucks and vehicles or combinations with more than four axles in 2024.

The City of Chino Hills strongly opposes any return of large truck traffic, arguing the restrictions address ongoing safety issues that widening alone may not fully resolve. 

Chino Hills City officials have said they are prepared to challenge any decision to lift the truck restrictions and note that Caltrans has indicated it may reevaluate the ban after the CEQA environmental process, regardless of whether the widening is built. 

This may be a moot point as Goodwin told the Globe a Caltrans Public Information Officer said the issue has been temporarily tabled while Caltrans, assuming they are re-evaluating how to move forward.

Data and updates come primarily from the City of Chino Hills-funded Iteris Truck Restriction Study, finalized 2023, earlier traffic studies, Caltrans collision records, and local reports of incidents.

State Senator Kelly Seyarto (R-Murrieta), San Bernardino County Supervisor Curt Hagman, and local public safety agencies support the Chino Hills residents.

Opposition Letters

• State Senator Kelly Seyarto
• San Bernardino County Supervisor Curt Hagman
• Chino Valley Fire District
• San Bernardino County Sheriff’s Department

Caltrans has until September to decide.

The Globe will continue to monitor the conflict and will update this story.