Parts of Highway 99/120 junction will close at night for upgrades. When and where
Drivers can expect nighttime closures of Highways 99 and 120 as part of the enlargement of their junction in Manteca.
The detours will begin at 8 p.m. Tuesday, July 15, on northbound 99 and shift to another part of the interchange later in the week. Each closure will be lifted early in the day to accommodate commuter traffic to the Bay Area and elsewhere.
The detours were in an email alert from the San Joaquin Council of Governments, which is overseeing the $48.2 million project. It will add a second lane on the ramp from eastbound 120 to southbound 99. It also will replace the Austin Road Bridge over 99 and create new freeway feeder routes in south Manteca.
Teichert Inc. of Pleasanton began construction in August 2024. The project is scheduled to be done by summer 2026.
The Austin Road Bridge was demolished in March. Its replacement will open near the conclusion of the overall project. The new bridge also will cross freight tracks that are part of an upcoming extension of the Altamont Corridor Express into Stanislaus County.
Details on the upcoming closures:
Northbound Highway 99 between the offramp and onramp for Austin, 8 pm. Tuesday to 4 a.m. Wednesday. This will involve a relatively short detour close to Austin.
The connector from eastbound 120 to southbound 99, 9 p.m. Wednesday to 6 a.m. Thursday. This detour will run for a mile north on 99 to the Yosemite Avenue exit, then back south on the highway to Austin and beyond.
Drivers can get future traffic alerts and other details on SJCOG’s project website.
