If one of your New Year’s resolutions was to go on more hikes in 2015, consider exploring trails in the East or South Bay the weekend of January 10th. The Golden Gate Bridge will be closed to vehicles for construction beginning  Friday night (12 a.m. on Saturday) until 4 a.m. on Monday, January 12th. The Bridge District is recommending that anyone who can avoid traveling by car between SF and the North Bay this upcoming weekend should do so.

The purpose of the closing is not to give Instagram a much-needed break from pictures of you and your friends on the top of Mount Tam, but to install the new Moveable Median Barrier (MMB) system on the bridge. If you’ve driven across the famous bridge before, you know that the number of lanes going in each direction changes depending on traffic and that oncoming traffic is separated by a line of plastic pylons.

These tubes are being replaced by the MMB, which is made of steel and concrete and will be put in place by “zipper trucks” to make new lane configurations. The new system will not only make it easier for the Bridge District to adjust the lanes, it will also prevent head on-collisions (and make it far less terrifying to drive in the left lane.) There were 16 fatalities from head-on collisions on the Golden Gate Bridge in between 1971 and 2007, and the bridge was made a Safety Awareness Zone in 2007. Head-on collisions still occur despite efforts on the part of the Bridge District, as the plastic lane markers do little to prevent them.

The project has been a long time coming; a study by the Bridge District in the 1980s concluded that a two-foot barrier, while valuable for preventing collisions, would result in too much congestion on the bridge. In 1996, the project was revived when smaller barriers became available. Although the current barriers, which will be 12 inches wide and 32 inches high, will result in “some operational tradeoffs,” the safety benefits outweigh the disadvantages. The trade-off you’ll mostly likely notice is that the inside lanes will be six inches narrower.

All in all, the barriers will be 13,340 long and cost $30.2 million dollars, with funding coming from Metropolitan Transportation Commission, federal funds, and toll revenue. They’ll extend on to route 1 in Marin, where there are additional changes coming on the southbound approach the bridge. Drivers will now merge onto the bridge from right to left instead of left to right and the speed limit on the Waldo Grade is being reduced from 55 miles per hour to 45 mph, which is the current speed limit on the bridge itself.

This work has been going on for a few weeks at night and will continue after the closing, but this coming weekend is the only major halt in service. If you must make the commute this weekend, the Golden Gate Ferry is adding additional service, the Golden Gate Transit bus will still be making trips over the bridge, and you can always take a roundabout route through the East Bay.  [The east lane will also be also open to bikers and pedestrians who want to take advantage of car-free bridge or enjoy a particularly athletic commute.] If none of those options sound appealing, there’s of course plenty of hiking to be done in San Francisco.