The existing State Route 160/Highway 4 interchange currently includes only two of the four possible interchange movements: the eastbound Highway 4 to northbound State Route 160 connector ramp, and the southbound State Route 160 to westbound Highway 4 connector ramp. The State Route 160/Highway 4 Direct Connector Ramps project will construct two new connector ramps, one connecting westbound Highway 4 to northbound State Route 160, and one connecting southbound State Route 160 to eastbound Highway 4.
The project scope includes adding an additional 12-foot auxiliary lane to the outside of existing State Route 160 in both directions between the State Route 160/Highway 4 Interchange and the East 18th/Main Street Interchange, as well as building a soundwall extension and retaining walls. The southbound State Route 160/Highway 4 separation structure will accommodate a future eBART extension in the median of Highway 4. KSN is providing all of the construction staking services for the project under the Construction Management Services Agreement for the Contra Costa Transportation Authority. Construction staking services are being provided in accordance with the Caltrans Construction Staking Manual.