MARTINEZ (CBS SF) – The Contra Costa Transportation Authority and Caltrans will conduct overnight highway and connector ramp closures in the state Highway 4/Interstate Highway 680 interchange starting Thursday night.

The four nights of closures, part of a multi-phase project to improve safety and reduce congestion in the interchange, includes closing the ramp from eastbound Highway 4 to northbound Highway 680 and the ramps from both southbound and northbound Highway 680 to eastbound Highway 4 each night.

On Thursday and Saturday nights, eastbound Highway 4 will be fully closed from Pacheco Boulevard to Solano Way, while the westbound side will be closed in the same area on Friday and Sunday nights.

The closures will allow vehicle traffic to move to the newly constructed connector ramps from northbound Highway 680 to eastbound Highway 4 and from westbound Highway 4 to northbound Highway 680.

Workers will also complete eastbound and westbound bridges at Grayson Creek and a widened section of pavement between Pacheco Boulevard and the Walnut Creek Bridge.

The closures are between 11 p.m. Thursday and 5 a.m. Friday, 10 p.m. Friday and 8 a.m. Saturday, the end of the night Saturday to 8 a.m. Sunday, and 8 p.m. Sunday to 6 a.m. Monday.

Motorists in the area during the closure windows are advised to drive cautiously and be alert for signage on detours around the construction area. According to Caltrans, the construction schedule is subject to change as weather permits.