A portion of state Highway 4 in San Joaquin County will be fully closed later this month to give way to road improvement operations, according to Caltrans officials.

The highway’s closure will be at the Middle River Bridge, west of Stockton in the San Joaquin Delta. It will begin at 10 p.m. Sept. 29 and conclude at 5 a.m. Oct. 2, Caltrans said.

Officials with the state agency said the road improvement operations include realigning curves and shoulders of the roadway, upgrading safety devices, and installing flashing beacons and additional street lighting.

A satellite image shows the sharp curve motorists must navigate on the eastern side of the Middle River Bridge. The nearby Union Point Restaurant, which was destroyed by fire in June, often attracted large crowds on summer weekends that contributed to traffic in the area. Caltrans this month plans to realign the roadway, add lighting and install other safety features in the area to improve traffic flows. (Google image)

Motorists driving on westbound Highway 4 are advised to take a detour starting at the Tracy Boulevard intersection. Take southbound lanes on Tracy Boulevard; westbound lanes on Interstate 205; northbound lanes on Mountain House Parkway; and north-westbound lanes on Byron Road before going back to Highway 4.

Those driving east on the highway are advised to reroute beginning at the Byron Road intersection. Take the south-eastbound lanes on Byron Road; southbound lanes on Mountain House Parkway; eastbound lanes on I-205; northbound lanes on Tracy Boulevard before returning to Highway 4.