Officials Celebrate Completion of the Highway 4 & Balfour Road Interchange Project in Eastern Contra Costa County

Press Release Issued by CCTA

Monday, December 10, 2018

Contact Information

Linsey Willis

Director of External Affairs, CCTA


Issued By


New Interchange brings much-needed traffic relief and improved safety to Brentwood

Brentwood, CA –The Contra Costa Transportation Authority (CCTA) and its partners, the Contra Costa Water District (CCWD), the Contra Costa Regional Fee and Financing Authority (ECCRFFA), the California Department of Transportation, and the City of Brentwood, held a ribbon cutting ceremony for the completion of the Highway 4 and Balfour Road Interchange Project. CCTA was joined by State, regional, and local officials to celebrate the completion of the interchange project, which brings much-needed traffic relief to Brentwood and Contra Costa County.

“Today’s ribbon cutting is one more symbol of the transformation taking place in Brentwood and Eastern Contra Costa County,” said CCTA Vice Chair and Brentwood Mayor Bob Taylor. “This project has reduced traffic, improved safety, and will have long term economic benefits for our region.”

The Balfour Road Interchange Project replaced the existing signalized, at-grade intersection at Balfour Road and State Route 4 with a grade-separated interchange and corresponding on- and off-ramps. The project involved raising State Route 4 to cross over Balfour Road, creating a new, safer undercrossing. This new configuration has eased traffic congestion and improved safety at this intersection for motorists, cyclists, and pedestrians.

Balfour Road Before
Balfour Road After 1

The project was one of the first in the state to use innovative drone technology to monitor construction progress. With assistance from engineering firm Alta Vista Solutions, CCTA flew drones equipped with a combination of LiDAR and camera technology to measure the volumes of earth that were moved during the $42 million dollar construction project. Utilizing this technology enabled CCTA to track construction progress firsthand and improve safety by taking workers out of live traffic. “We are always looking for new ways to increase safety and efficiency on construction projects,” stated CCTA Executive Director Randy Iwasaki. “Drones give us aerial views of the site that were hard to come by before, making it safer for surveyors to do their job and helping us manage the large volume of dirt that was used to improve this intersection. This technology also allowed us to monitor environmentally sensitive areas without disturbing the habitat.”

Fun Facts about the new interchange

Innovation on this project extended beyond the use of technology. CCTA also facilitated a collaborative, multi- agency agreement that saved both time and money for the Balfour Road Interchange project. Prior to the start of construction, CCTA and the Contra Costa Water District (CCWD) worked together to gain Caltrans approval to leave the 90-inch Los Vaqueros Pipeline in place along the project alignment, essentially building the new highway infrastructure in conformity with the existing pipeline. Rather than a complete relocation of the relatively new pipeline, CCTA, CCWD and Caltrans arrived at a design that maintained the reliability and longevity of the infrastructure, worked for all agencies, reduced environmental and community impacts – which saved Contra Costans approximately $18 million in environmental permitting, property acquisition and construction costs.

About The Contra Costa Transportation Authority

The Contra Costa Transportation Authority (CCTA) is a public agency formed by Contra Costa voters in 1988 to manage the county’s transportation sales tax program and oversee countywide transportation planning efforts. CCTA is responsible for planning, funding and delivering critical transportation infrastructure projects and programs that connect our communities, foster a strong economy, increase sustainability, and safely and efficiently get people where they need to go. CCTA also serves as the county’s designated Congestion Management Agency, responsible for putting programs in place to keep traffic levels manageable. More information about CCTA is available at

About the Highway 4 Projects

The Highway 4 projects include improvements that will help modernize eastern Contra Costa County. The projects expand Highway 4 from four to eight lanes between Loveridge Road in Pittsburg to just west of State Route 160 in Antioch, from two to four lanes from Lone Tree Way to Balfour Road in Brentwood, add missing connector ramps at the State Route 160/Highway 4 interchange, and add a BART extension from Pittsburg to Antioch (eBART). This will greatly improve transit accessibility for the region, help reduce traffic congestion, and enhance the quality of life for the more than 250,000 residents of eastern Contra Costa County. The projects have been carefully staged to keep 130,000 vehicles per day moving as major construction and demolition work continue. These projects, plus previously constructed projects in the region, bring the total investment in East County to $1.3 billion, including State, Federal, Contra Costa Transportation Authority Measures C and J, regional bridge tolls, and other funds.

For additional information about the Balfour Road Interchange Project, please visit