Beginning today at 10 p.m., the ramp from northbound Highway 1 to northbound Highway 101 will be closed until 10 a.m. Saturday, according to a spokeswoman for the Doyle Drive replacement project.
For the same twelve-hour period from Saturday night to Sunday morning, the ramp from southbound Highway 101 to southbound Highway 1 will be closed, project spokeswoman Molly Graham said in a statement.
Although the closures were scheduled for a time when traffic volumes are lowest, motorists are advised to avoid travel through the impacted area if making trips that are optional, Graham said.
The two overnight closures will allow a temporary shift of northbound and southbound traffic to the newly completed section of the Ruckman Bridge, which is part of the Presidio Parkway that will replace the structurally and seismically deficient south access road from Highway 101, Doyle Drive.
During the closures, detour signage will reroute motorists traveling northbound from Highway 1 to Highway 101 through Geary Boulevard, Van Ness Avenue, and Lombard Street.
Between Saturday and Sunday, drivers will be directed to continue on Highway 101 to Geary Boulevard and to Highway 1 at Park Presidio Boulevard.
Built in 1936, Doyle Drive, the existing 1.5-mile stretch of roadway connecting the San Francisco peninsula to the Golden Gate Bridge, carries more than 100,000 vehicles each weekday and requires replacement due to the effects of time and continual use.
The replacement project is a collaboration between Caltrans and the San Francisco County Transportation Authority. Construction of the Ruckman Bridge is expected to be completed by midyear.
One lane of southbound Highway 1 traffic will be closed for approximately four to six months, according to project officials, and drivers should be aware of changes to the roadway alignment and southbound merge during that time.
More information about the project can be found by visiting www.presidioparkway.org.
Patricia Decker, Bay City News