Moveable Median Barrier Installed on the Golden Gate Bridge

The Golden Gate Bridge became safer for drivers after the weekend of January 10, 2015, when the Golden Gate Bridge, Highway and Transportation District installed a new Moveable Median Barrier (MMB) to virtually eliminate the possibility of a head-on collision. The solid, semi-rigid Barrier is made up of 3,517 interlocking steel and concrete units, each weighing 1500 pounds and standing 32 inches tall. To accommodate the narrow lanes on the Golden Gate Bridge, the Barrier was constructed to be just 12 inches wide. It replaces the yellow plastic pylons that had visually separated northbound and southbound traffic ever since lane management began in the early 1960’s.

The MMB is the result of many years of effort to bring this important lifesaving feature to the Golden Gate Bridge. It cost $30 million to design and install, with $20 million provided by state funds through the Metropolitan Transportation Commission. Since 1970, there have been more than a hundred head-on collisions, leading to 16 fatalities.

The District held a ribbon cutting ceremony on January 11 at Vista Point. Democratic Leader Nancy Pelosi, Congresswoman Jackie Speier, crash survivor Dr. Grace Dammann, and Metropolitan Transportation Commissioners Steve Kinsey and Bob Alvarado all shared their support of the new barrier.

The MMB is moved by a crew of two District employees driving a “zipper” truck. The crew picks up the Barrier from one end of the truck and then offsets the barrier by about ten feet on the other end. The lane change operation typically takes about thirty minutes to complete.

The barrier is typically positioned to allow three lanes of traffic southbound and three lanes northbound overnight. In the morning, the Barrier is shifted to allow four lanes southbound into San Francisco, to accommodate commute traffic. It then moves back to three south, three north through the middle of the day. In the afternoon, it shifts to four lanes northbound, two lanes southbound to accommodate the evening commute traffic.

Since the barrier was installed, there have been very few significant collisions into the barrier. In those instances, it is clear that the barrier prevented vehicles from crossing into oncoming traffic. The barrier is proving to be a mighty and simple force for safety on the iconic Golden Gate Bridge.