California’s department of transportation (Caltrans), the Solano transportation authority and the Metropolitan Transportation Commission have broken ground on a major project to reduce congestion and improve safety on the Interstate 80/Interstate 680/State Route 12 interchange.

The route is used by more than 150,000 motorists every day.

Caltrans director Malcolm Dougherty said truckers, businesses and motorists will all benefit from this project.

"This investment in our infrastructure strengthens the economy and helps improves the quality of life in northern California."

"This investment in our infrastructure strengthens the economy and helps improves the quality of life in northern California," Dougherty said.

The first phase of a seven-phase project includes construction of a new Green Valley Road overcrossing above I-80 about 200ft east of the existing overcrossing, a new on-ramp to westbound I-80/SR-12 and an extension to the connector ramp from westbound I-80 to SR-12.

The first round of improvements will require an investment of approximately $61m and will be completed by mid-2016.

The project received $15m from Proposition 1B, a 2006 voter-approved transportation bond.

The remaining six phases of the project will be carried out as funding becomes available and will include new interchange at Red Top Road and I-680; new westbound connector ramp from westbound I-80 to southbound I-680; and realignment of I-680 between I-80 and the Lopes Road exit in Cordelia.

Among other improvements are realignment of the connector ramp from SR-12 to eastbound I-80 and the extension of several local streets leading to I-80 and SR-12.

The upgrades at Interstate 80/Interstate 680/State Route 12 interchange are part of an ongoing effort to improve the transportation infrastructure in Solano, Sonoma and Napa counties.