11 June 2026

New City of Chino Hills Statement on CalTrans' Proposed "Improvements" to Carbon Canyon Road

This just in from the City of Chino Hills regarding the proposed "improvements" by CalTrans to Carbon Canyon Road (State Route 142):

 



The City of Chino Hills remains firmly opposed to and is prepared to challenge any decision made by the California Department of Transportation (Caltrans) that would allow large truck traffic to return to State Route 142 (SR-142) and the “S-Curves” on Carbon Canyon Road. Statements made by Caltrans during a June 10 public hearing indicated the agency intends to remove current truck restrictions, regardless of whether roadway safety improvements such as widening of the “S-Curves” are made or not.

For more than seven years, the City worked alongside residents, community members, regional partners, and legislative representatives to address the significant safety concerns posed by large truck traffic of vehicles over four axles along Carbon Canyon Road. Those efforts resulted in truck restrictions that took effect in May 2024, which protect public safety and enhance the quality of life for residents. The City remains committed to ensuring those protections remain in place permanently.

Caltrans is accepting public comments on the project through June 17, 2026. Residents are encouraged to submit comments to be considered as part of the environmental review process by email at D8.1M780.Comments@dot.ca.gov. The City has requested that Caltrans conduct a follow-up public meeting in person to provide additional opportunities for community engagement.

To learn more about about this topic and its history, the June 10 Public Hearing, and how to submit public comments to Caltrans, visit  www.chinohills.org/CarbonCanyon. The City remains committed to advocating for the safety of our community and will continue to provide information related to the project through this website page as it becomes available.

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Carbon Canyon Road S-Curve Zoom Meeting Summary

Last night, CalTrans District 8, which covers the San Bernardino County portion of Carbon Canyon belatedly held a public Zoom meeting to discuss the project to "improve" the S-curves on Carbon Canyon Road, which is California Highway 142, with around 100 concerned residents gathered at the McCoy Equestrian Center Barn for the gathering.  The confab included a relatively brief, pro-forma recitation by CT officials of an overview, background and timeline of the proposed project, which could take up to four years to complete including environmental review, design and construction, while public comment is taking place this month and in July.

As with other projects like this, there are the build and no-build alternatives, but the claim is that the work to widen the S-curves and install retaining walls and other elements is to improve safety, even as the completion of the project would allow more volume because it was made abundantly clear that the ban of trucks of 5 axles or more, implemented a couple of years ago, with several years of concerted action from the cities of Brea and Chino Hills, would almost certainly be rescinded either way, meaning whether the "improvement" was made or not.

Also striking was the reiteration on several occasions by a CT official that this project came about because of public concerns of trucks crossing the centerline striping at the S-curves and so the claim was that this effort to widen the roadway and other aspects was the only real response the agency could make.  The obvious problem with this from the standpoint of those who spoke during the Q&A, considered informal so not recorded for the public record, and the oral comment portion, which was formalized and recorded, is that this was not the reason for the concerns.  

It should be noted that none of the dozens of persons who asked questions or spoke during the meeting, including a former Chino Hills councilmember and mayor, the current mayor and a city official, voiced support for the project.  So, if CT's contentions about concerns from the public were that this project was warranted, why did the public who expressed current concerns agree en masse that this is not what was intended when complaints were registered with the department?

Another remark by a CT official that raised eyebrows was the statement that the project was not intended to add more trucks to traffic on the state highway, but to more broadly improve traffic flow.  As many speakers pointed out, as often as accidents occur at the S-curves—a property owner with expensive cast-iron fencing and walls has, yet again, had these plowed into by a car within the last couple of weeks, and a section at Carriage Hills Lane has been the site of many crashes that have caused power outages throughout the Canyon—the way this section is constructed actually serves to slow most traffic down.  Yet, CT has insisted on adding so many signs, in the belief that this will somehow deter dangerous driving, when only enforcement can mitigate this, that it is almost comical to see how cluttered the roadway has become, yet the behavior continues.

It was also remarked that, while this work may be viewed by the agency as necessary and effective, the isolation of the S-curves from the rest of the state highway seems more than self-defeating.  For example, there are curves in Sleepy Hollow, principally at the east entrance to Rosemary Lane, where trucks routinely cross the centerline and have, in fact, swipes mailboxes and vehicles, while others routinely honk their horns as a warning, but with very limited sight lines.  There is no way to remediate the highway in that location and this is true at another curve to the west under which Carbon Creek passes, while sections in Brea may well involve the same general issues.

Other questions and comments concerned the absolute bare minimum of public notice, the inadequacy of holding a Zoom meeting so that an in-person gathering was requested, the fact that the documents so far prepared were insufficient, the call for a permanent ban on trucks—which CT personnel said would involve the cities going through a similar process to the current one (meaning years of struggle), and more.  One commenters wanted to know who was behind this project in terms of either the complaints registered that led to the interpretation that this work was the best response or who may be lobbying (a common perception is that Amazon, readying to establish a distribution center just outside the canyon on the 142 [the Valencia Avenue portion] in Brea, is behind this) for the work.


Perhaps the most remarkable claim from CT officials was that the ban instituted in the last couple of years was temporary and was always intended to be so.  While City of Chino Hills officials were clear in saying that this was not the case, the response from the department was that it was in the agreement signed by Chino Hills and Brea.  The obvious question is:  what will be the future communications between the municipalities and Cal Trans about this vital issue?

There will, of course, be more to come, but the salient matter right now is for those concerned about this project—and nothing said by CT staff alleviated any concerns, from what this observer heard and saw—this is the time to comment, during this and next month.  There is also the Hope for the Hills campaign against the project

05 June 2026

Chino Hills Historical Society Presentation This Monday: Before Chino Hills State Park

This Monday the 8th at 7 p.m., at the Chino Hills Community Center, 14250 Peyton Drive, across from Ayala High School, the Chino Hills Historical Society hosts a presentation on some history of the area that became Chino Hills State Park, as well as some of the park's history.

If you've been in this amazing local resource and wondered how Rolling M Ranch, the park's headquarters and where there is a great campground, or Telegraph Canyon got their names, you can learn that by attending the talk.

San Bernardino Guardian, 20 September 1873.

If you didn't know that an international airport was proposed for much of the parkland, come on by and hear more about that, as well.

Paul Spitzzeri will discuss some of what the land was used for prior to its preservation and Hills for Everyone President Claire Schlotterbeck, who was deeply involved in the movement for the establishment of the Park, will share some of that story, as well.

Chino Champion, 20 October 1971.

We hope to see you there!