Atherton officials say the contractors are making significant progress in installing a new drainage channel along Marsh Road.
Contractor Granite Construction has finished most of the demolition work and is getting ready to pour concrete.
The road is expected to reopen to two-way traffic on Aug. 13. Construction hours are Monday through Friday from 8 a.m. to 8 p.m. and Saturday from 8 a.m. to 5 p.m.
Until then motorists must use detours, including Woodside Road, 5th Avenue, Ringwood Avenue and Willow Road to get around the construction.
The town is replacing a deteriorating stone and concrete drainage channel with a cast-in-place concrete culvert. In addition to draining water from much of Atherton, the culvert acts as a retaining wall on Marsh Road.
The project also involves replacing the chain link fence which had proved ineffective at keeping errant motorists from plunging into the channel with a steel guard rail.
To ease the impacts of the Marsh Road detour during the project period, the town has added more pavement markings and traffic control signs in North Fair Oaks.