The first step to restrict big rigs on Carbon Canyon Road took place Wednesday when a preliminary study on the state highway was unveiled to approximately 50 residents at the Chino Hills public works commission meeting.
Transportation engineering consultant Clyde Prem said trucks are scraping the roadside and causing ten-to-20 minute traffic delays navigating the switchbacks and steep grades.
He said a process exists where Caltrans can restrict truck traffic but it is rarely undertaken.
It includes sending resolutions to two Caltrans districts because the 8.4-mile road, known as State Route 142, is located in Brea and Chino Hills.
Traffic, legal, and environmental offices in Sacramento would become involved in the effort.
The study was commissioned last November after concerns mounted about the volume of traffic on Carbon Canyon Road and the increased amount of large trucks using the road as a bypass route.
Traffic congestion is also caused by the terrain, school bus stops, uphill grades, a narrow bridge, and the signals at Olinda Place and Ruby Street on the Brea side, according to the study.
The report revealed 92 collisions resulted in 153 injuries and three fatalities between 2010 and 2015. Of the injuries, 52 were in Chino Hills and 101 in Brea.
Unsafe speed and improper turning were the two leading causes of collisions.
The highest number of accidents occurred at the following areas: Chino Hills Parkway, the switchbacks, Canyon Hills Road, the Discovery Center which is the entrance to the Chino Hills State Park, and Valencia Avenue and Lambert Road on the Brea side.
Charlene Peterson, who has lived in the canyon for 38 years, suggested that turnouts be added and shoulders widened. She said the roadway on Brea’s side contains raised markers “so you know when you cross the line.”
Eldona Reasoner Arns, a 47-year resident, said signs should be installed showing driveway locations so that drivers are cautious at those approaches. She noted that driveway approach signs are on the Brea side but not on the Chino Hills side.
Public works director Nadeem Majaj said the improvement ideas were doable and would be pursued.
Mr. Majaj said the city has been working with both Caltrans District 8 and Brea. Brea, in turn, is in contact with Caltans District 12.
“I think this is the first time in the history of the city that we’ve gotten all parties to talk,” Mr. Majaj said. “The goal is to work with Caltrans to limit the size of trucks to the capacity of the road.”
Advisory signs state that trucks more than 50-feet in length are not advised on certain sections of the road but 65-feet trucks are allowed on California highways.
Commissioner Bill McDonnell said it is the first time he has seen progress made on Carbon Canyon Road in the 20 years he has served on the commission. “If we can get rid of this truck traffic that will be a major victory,” he said.
Residents said trucks cross the yellow lines on the switchbacks endangering oncoming traffic.
Caltrans has determined that widening is not possible because of the terrain and development alongside the road.
The commission voted to support the second phase of the study that would address truck traffic, safety, and traffic flow along Carbon Canyon Road.