Detour alert: Key ramp will close at night for Highway 99/120 interchange upgrade
Five straight overnight closures are needed at part of the Highway 99/120 interchange upgrade in Manteca.
They will begin Sunday, Oct. 19, on the ramp connecting eastbound 120 with southbound 99. A detour will be in place from 10 p.m. each day to 5 a.m. the next morning, into early Friday.
Drivers will go a mile north on 99 to Yosemite Avenue, then turn south again toward Ripon and Stanislaus County.
A separate nighttime closure will involve southbound 99 between the onramp and offramp for Moffat Boulevard. The detour will be just west of the freeway between Monday night and Friday morning, from 9 p.m. to 5 a.m. each time.
The $48.2 million project will add a second lane to the ramp from eastbound 120 to southbound 99. It also will provide a fourth lane on southbound 99 between 120 and Austin Road.
Construction started in August 2024 by Teichert Inc. of Pleasanton and is expected to take until summer 2026.
The project is sponsored by the San Joaquin Council of Governments. Drivers can get updates at www.sjcog.org.
