A decades long dream to widen State Highway 70 from Chico to Sacramento, California, is coming to fruition and will improve traffic flow and safer passage through the agricultural area.

“The project is designed to improve safety,” says Cameron Knudson, Project Manager for Caltrans in Marysville.

The two-lane highway was experiencing traffic accidents at a rate 2.5 times higher than similar routes through the rest of the system. In the past decade, there have been 52 fatalities on Highway 70 in this area. Impatient drivers often attempt to pass slower moving vehicles, including tractors and other farm equipment. Farmers in the area grow peaches, prunes, rice, and other foods. Additionally, residents and farm vehicles are entering and exiting the highway from driveways.

“People will be able to get around and safely pass slower moving vehicles,” Knudson explains. “We have people moving goods and services. These extra lanes and buffer lanes are a huge improvement to the local area and make the road more reliable, which helps the economy.”

Highway 70 is the main commuter route between Chico and Sacramento. About 13,400 vehicles travel daily on the road at the Yuba-Butte County line. Butte County is the largest county in Northern California not served by a four-lane road, says Jon Clark, Executive Director of the Butte County Association of Governments (BCAG). More than 200,000 people live in the area.

In addition to the region’s agricultural component, the area is full of recreational areas, for camping, fishing, and other outdoor activities. Some people commute from the Chico area to Sacramento, about 90 miles to the south. Others access the higher education offered in Butte County.

“There are a lot of benefits to the local community,” Knudson says. “It will greatly improve the safety of the route.”

Caltrans partnered with the Butte County Association of Governments (BCAG), which provided funding along with the state safety program, for this project. The two entities have been working toward a solution for Highway 70 and obtaining the necessary funds for the past 30 years.

“It has been a long-term goal of ours,” Clark says. “I am happy to see it finally getting done. Most of the feedback we hear is positive.”

This current project is one of several improvements undertaken along the Highway 70 corridor in the region.

“The sections we have complete in Butte County to the north are much more comfortable to drive than the previous two-lane sections,” Knudson says.

In 2019, Teichert of Sacramento completed a $48.5 million project, widening 3 miles between Ophir Road and Palermo Road and finished one year early. Caltrans and BCAG partnered on this 3-mile section of Highway 70, south of Oroville.

The $42 million safety improvements on Highway 70 between Palermo Road and Cox Lane in Butte County began in September 2020 and was completed by Knife River Construction of Chico in November 2021. BCAG also partnered on this two-year project.

Caltrans replaced the aging Simmerly Slough Bridge with a new $60.4 million structure north of Marysville on Highway 70 in summer 2020 and 2021. MCM Construction of Sacramento received the contract and began work on the five-span bridge in August 2019 in Yuba County.

There is another Highway 70 safety improvement project under way to the south in Yuba County. DeSilva Gates Construction of Dublin, California, broke ground in April 2022 on a $122 million, 9-mile stretch of Highway 70 between Laurellen Road and the Yuba-Butte County line. Completion of the Yuba County project is expected in two years.

“When these last two projects are completed, the road will be five lanes between Marysville and Oroville,” Knudson says.

The $65.8 million Butte County project – including design and right of way – entails widening 3 miles of the road from two lanes to five lanes, including two northbound lanes, two southbound lanes, a 14-foot-wide center two-way left turn lane (TWLTL) and standard shoulders. The TWLTL also acts as a buffer to separate the traffic. The current road has some standard shoulders, but some are not up to current standards. Caltrans engineers designed the current widening projects.

The safety project will also provide a 20-foot-wide clear recovery zone that starts at the edge of traveled way, so if a vehicle veers off the road, it has space to regain control and stop or re-enter the highway without running into trees, utilities, shrubs, or other obstacles.

“We are flattening the slopes on the shoulders,” Knudson says. “If the driver of a car drives off the road, they will be less likely to hit something.”

The project also includes upgrading the cross drainage and extending culverts to maintain water flows across the highway and improves the roadside ditches. The work will convert three existing bridges into northbound lanes and building one new concrete box-girder bridge over Honcut Creek for the new southbound lanes. The single-span bridge has cast-in-drilled-hole pile foundations, arches between the piers and a concrete deck, all cast in place.

At the south side of the creek, a levee protects the reclamation and irrigation district 10 area in Yuba County. Caltrans obtained federal and state permits for the work and is replacing habitat and mitigating tree loss. The agency purchased credits to plant trees in other areas and will also plant trees along the Honcut Creek area where they were removed. The project will avoid impacts to fish and salmon habitats and the flood plain.

“The permitting was not easy and took a lot of coordination and teamwork with federal and state regulatory agencies,” Knudson says, but the agency was successful.

Teichert and joint venture partner, MCM Construction, received the $50 million construction contract for the current project. MCM is building the structures. Work began in late summer 2021.

“We’re building the longest single-span bridge in Caltrans history,” says Danny Warren, Project Manager with Teichert.

Teichert has setup a mobile crushing plant at a quarry owned and operated by one of its sister companies, Mathews Ready-mix, where it is generating the 75,000 tons of aggregate base for the project. The site is located just a few miles north of the project.

“Being able to utilize our materials assets at this local resource is a major help in keeping cost and construction-related traffic down,” Warren explains.

Caltrans uses automated guidance systems on many of its projects, including this one. Therefore, the contractor is using a 3-D model and equipment with GPS to construct the project and check grades.

“It’s much faster and less labor intensive,” Knudson says. “It saves a ton of time and quite a bit of money.”

Teichert will still obtain a survey for the finish grade, Warren said. Caltrans inspectors also spot check the grade to ensure it is being built to the design specifications.

Caltrans has decreased speed on the segment to 45 miles per hour through the construction project to help improve safety in the construction zone, and traffic continues to flow.

“The project is built largely offline,” Knudson said. “The work is being constructed behind K-rail with not a lot of disruption of traffic.”

The project is scheduled for completion by late 2023.

“That’s pretty quick considering the bridge and the new highway we are putting down,” says Warren, who praised the collaboration among all of the parties involved.

“I am proud of the cooperation between Butte County, BCAG, Caltrans and the project team for overcoming some of the challenges,” Knudson agrees. “Everything is going well.”

Photos courtesy of Caltrans and Teichert