Big repairs for Marin Headlands’ tiny tunnel
A narrow little tunnel that doesn’t make the radio traffic reports or even appear on Google Maps is about to create months of congestion in the Marin Headlands.
The Baker-Barry Tunnel, known to many who visit the Golden Gate National Recreation Area as “the fiveminute tunnel,” will close for repairs Jan. 2. It isn’t scheduled to reopen until early May.
Built nearly a century ago to connect Fort Baker and Fort Barry, the one-lane tunnel on Bunker Road carries headlands visitors in cars, trucks or on bikes beneath the Waldo Grade. Because the tunnel has just a single lane, with skinny bike lanes on each side, traffic signals control access with the direction changing every five minutes.
Closures are not unusual, because
the sewer and water pipes inside the half-mile-long passage often break and need repairs. But those shutdowns usually last days or hours — not months.
Bunker Road is not a commuter thoroughfare, but it is one of two driving routes into the headlands. The other, Conzelman Road, snakes along the rugged coast west of the Golden Gate Bridge, which lures throngs of photo-taking tourists.
“We have two arteries into the Marin Headlands, and we’re looking at closing one for five months,” said Nathan Hale Sargent, a Golden Gate National Recreation Area spokesman. “When the tunnel does close, it will be a major disruption.”
Drivers and cyclists — and park officials — will get a chance to prepare for the shutdown with a series of part-day closures: from noon to 4 p.m. on Dec. 5 and 8:30 a.m. to 4 p.m. on Dec. 6 and 7.
When the tunnel is closed and traffic is confined to Conzelman Road, park officials expect the biggest problems to be at the already congested lookouts where tourists, view-seekers and photographers pull in and out of traffic and often double-park.
“Our main concern when the tunnel is closed is maintaining a safe flow of traffic in the Marin Headlands,” Sargent said.
Because the headlands are part of a national park, the Federal Highway Administration is drawing up a trafficflow plan, which may limit access to bridge overlooks during peak traffic times. When the plan is finished, the park service will post it at www.nps.gov/goga/learn/ news/2016-tunnel-closure.htm .
Until then, officials suggest that tourists avoid the mostcongested times in the Marin Headlands, including weekdays between 3 and 7 p.m. and Saturdays and Sundays after 2 p.m. Photographers are advised to find other places to take pictures of the Golden Gate Bridge, including Fort Baker and Crissy Field. And bicyclists, who will still be permitted to use Conzelman Road, are advised to avoid riding during the busiest times or to choose other places to pedal.
The tunnel shutdown will make for longer trips, albeit with breathtaking scenery, for visitors, park employees and others who work in the headlands.
“It’ll be a bit of an inconvenience,” said Chrissy Sullivan, 27, a natural resources specialist for the National Park Service, who works at Fort Cronkhite, lives in San Francisco and travels through the tunnel several times a day for her job. “Luckily, the long way around is not too bad.”
The construction project, expected to cost $5.2 million, is intended not only to improve but also preserve the Baker-Barry Tunnel, which is listed in the National Register of Historic Places. Built in 1917 and 1918, with walls and ceilings supported by lumber, it was enlarged and covered with concrete from 1937 to 1939.
In addition to the troubles with the aged sewer and water pipes along the north side of the tunnel, water seeps through the walls, leaving a slimy and slick coating on the roadway. Workers will restore and reseal the tunnel walls, replace the sewer and water pipes, and install brighter lighting that consumes 40 percent less electricity than the current system, Sargent said.
They’ll also clean out 20 culverts and repave the roadway. The tunnel won’t be expanded, and the lane widths won’t be changed.
Even so, and despite the traffic headaches the tunnel closure will deliver, Sargent said the upgraded tunnel is worth the trouble.
“While we’re biting the bullet for this five-month closure,” he said, “the hope is that it will minimize closures in the future.”
“We have two arteries into the Marin Headlands, and we’re looking at closing one for five months . ... It will be a major disruption.” Nathan Hale Sargent, Golden Gate National Recreation Area spokesman