Crews this weekend shut down the Golden Gate Bridge to install a new barrier designed to make the span safer for motorists.
The California Highway Patrol and construction crews started closing bridge roads around 9:30 p.m. Friday.
Golden Gate Bridge officials have been talking about installing the $30 million divider since the late 1990s. The 52-hour closure of the iconic bridge started at 12:01 a.m. Saturday and ends at 4 a.m. Monday.
Part of the installation will require crews to remove plastic pylons that currently separate the northbound lanes from the southbound lanes. The pylons will be replaced by high-density concrete barriers that will be pinned together in a chain down the middle of the bridge.
"They've been found to be very effective in preventing head on collisions," Golden Gate Bridge Chief Engineer Ewa Bauer said of the concrete barriers.
Bauer said drivers in the middle lanes will have to adjust and get used to the lanes, which will lose six inches of width.
As of Saturday night, the bridge is expected to open on-schedule.
HOW TO GET AROUND DURING THE CLOSURE:
During the closure, Golden Gate Transit buses will still be allowed to cross the bridge and will run on their normal weekend schedule. Emergency vehicles also will be allowed on the bridge during the closure.
Vehicles traveling from the North Bay will have to use either the Richmond-San Rafael Bridge or Bay Bridge to get into San Francisco.
Golden Gate Ferry will expand its service to and from Larkspur and San Francisco to include late night trips.
There will be 15 departures from Larkspur to San Francisco starting at 5:45 a.m. Jan. 10 through 12:35 a.m. Jan. 11. Eleven of the departures from Larkspur to San Francisco will be half-hour high-speed runs.
There are 14 departures from San Francisco to Larkspur from 6:20 a.m. Jan. 10 through 1:10 a.m. Jan. 11. Eleven of the departures will be high-speed runs.
The Sausalito Ferry to and from San Francisco will operate on its regular weekend schedule. The trip takes a half-hour one way.
The bridge's east sidewalk will remain open to pedestrians and bicyclists, but the west sidewalk and parking lots at both ends of the bridge will be closed to the public.
San Francisco Municipal Railway 28-19th Avenue buses will be allowed to operate through the tunnel under the Bridge Toll Plaza.
Access roads that lead to the bridge will start closing at 9:30 p.m. Jan. 9.
U.S. Highway 101 in Marin County will close at the Marin City/Sausalito exit. There will be no southbound access from Marin City to the bridge and there will be no northbound access from Alexander Avenue.
Access to northbound Highway 101 will be available from Spencer Avenue and Rodeo Avenue.
In San Francisco, the Highway 101 closure will be at Doyle Drive and Marina Boulevard. There also will be a closure at the intersection of Park Presidio Boulevard and Lake Street. There will be no northbound access to Highway 101 between those exits and the bridge.
WHEN BRIDGE REOPENS:
A new merge will be different for southbound vehicles. Drivers currently merge from left to right -- the new merge will be from right to left, officials said. In addition, the speed limit will be dropped to 45 mph from the current 55 mph on the decent down the Waldo Grade.
After the installation of the new barrier, transit officials said the two inside lanes on the bridge will lose six inches of width. Officials advise motorists to take it slow and get used to the new driving conditions once the bridge reopens.
Bay City News Service contributed to this report.