Baker-Barry Tunnel in the Marin Headlands
(AKA “5 Minute Tunnel” or “Bunker Road Tunnel”)
Bunker Road near Alexander Ave., Sausalito CA 94965
Alert: The Baker-Barry Tunnel will be closed to all traffic from January 9, 2017 to early May, 2017 for repairs. There will also be a one-day closure on Thursday, Dec. 29, 2016. We have detour routes below.
A Tunnel with Many Names: The Baker-Barry Tunnel is often called the Bunker Road Tunnel (since Bunker Road goes through it) or “The 5 Minute Tunnel” since it is a one-way tunnel with a stoplight that lets each direction pass through for five minutes at a time.The most common informal name with locals is “The Five Minute Tunnel” but Bker-Barry Tunnel (named after the two old military bases it connected) is the official name.
Detour Routes During 2017 Construction
The Baker-Barry Tunnel will be closed from January 9, 2017 (moved back a week from the original January 2) to early May, 2017 for repairs, and additional one-day closures will take place in December for preparation work. The small parking lot at Battery Spencer on Conzelman Road will also be closed.
The road will be resurfaced, new lights installed, and the old and leaking water and sewer lines mounted inside will be replaced. The detour routes to reach Rodeo Beach, the Marin Headlands Welcome Center, the Marine Mammal Center, Fort Cronkhite, etc. are very scenic and do not require that much additional driving time.
Use Conzelman Road, which begins by the Golden Gate Bridge, to go west along the bluffs of the Marin Headlands to reach the Conzelman-McCullough Roundabout. Turn right onto McCullough Road, which will snake through the hills and reach Bunker Road just downhill from the northwest side of the Baker-Barry Tunnel.
If you wish, you can also stay on Conzelman Road all the way down to the Lower Fisherman’s Parking Lot, and then turn right there. In just a few yards you can then turn right on Field Road, which will wind downhill to Bunker Road near Rodeo Lagoon.
Insiders Tip: If the traffic increase on Conzelman Road grows too much as a result of the tunnel closure the Park Service has warned that they may block off sections of Conzelman to cars (and even to bikes) at some time from January through May.
Note: To get Google Maps to show the correct route without routing us through the closed tunnel I used the Directions function for a walking map. The street equivalent for the one small section of the map that uses a trail is to just stay on Alexander Ave.
Why is it Sometimes Called “The 5 Minute Tunnel?”
The Tunnel allows only one-way traffic in each direction between the old military bases Fort Baker (next to the Bay) and Fort Barry (higher up the hills in the Marin Headlands). There are stoplights at each end of the tunnel. When one side goes red there is a delay for mid-tunnel traffic to clear. The opposite side stoplight then goes green and stays green for a full five minutes, during which the tunnel is a one-way street.
After the five minutes are over the green light turns red, there’s another delay and then the opposite side goes green for five minutes. They alternate like this 24 hours a day.
Many local residents don’t know the official name of the Baker-Barry Tunnel, but refer to it as “the 5 minute tunnel near the Golden Gate Bridge” or “near Sausalito.” The term “one way tunnel” will also sometimes be used.
Baker-Barry Tunnel Maps
Scroll down for interactive maps and a Google Earth map of the same area so you can see where the road vanishes as it goes through the tunnel. Click any map to go to larger online version.
Photo Credit: National Park Service. Thanks to the NPS for their great liaison with the press.