It's known as "the maze," a congested tangle of interstate highways that link San Francisco with the East Bay cities of Oakland, Berkeley, and beyond.
Residents here woke up Sunday morning to the news that parts of this crucial interchange, one of the busiest in America, had melted and collapsed after a gasoline tanker truck crashed and exploded.
No one was killed in the early morning accident. But residents are bracing for severe traffic disruptions in the weeks and months ahead, as parts of I-880 and I-580 are repaired.
The episode recalled vulnerabilities felt in the not too distant past. The 1989 Loma Prieta earthquake caused a similar collapse, also damaging a vital San Francisco-Oakland link, the Bay Bridge. And then, there was that image of a fireball melting steel to topple a piece of the urban landscape.
San Francisco Mayor Gavin Newsom said the accident highlighted how fragile the region's transportation network is to an earthquake or terrorist attack. "It's another giant wake-up call," Mr. Newsom said.
City officials ought to be planning for far worse possibilities, warns Fred Millar, a homeland security consultant and hazardous materials expert. Release of chlorine, a gas that's still being shipped through major urban areas, could kill tens of thousands, he says. And propane and liquid natural gas explosions could dwarf Sunday's fireball in Oakland.
More than 800,000 hazmat shipments are trucked around the US every day, according to the Federal Motor Carrier Safety Administration. Each year, roughly 200 trucks are involved in fatal crashes and 5,000 in nonfatal crashes.
Gasoline isn't in the top tier of explosives, flammables, or toxins. But, says Dr. Millar, since it is so ubiquitous and can – as the Oakland incident demonstrated – be quite destructive, cities should not be letting gas trucks go in tunnels, near bridges, or on major commuter highways if it can be helped. Gasoline tankers have been getting bigger over the last 30 years, and their metal skins remain thin for economic reasons, he says.
Dangerous cargoes, says Millar, ought to be expedited or rerouted around cities using existing beltway highways and tracks. New York City has been forcing hazmat trucks to avoid the metropolis for years after an incident with an LPG truck on the George Washington Bridge. The city won a court case brought by the trucking industry, he says, yet other cities have been slow to implement rerouting policies except at obvious chokepoints like bridges and tunnels.
While the Oakland incident is sure to prompt another look at whether cities are doing enough to secure transportation linchpins from accidents and attacks, this episode may also reveal that even overcrowded systems have some flexibility, experts say.
"In an emergency like this one, it's clearly feasible to establish detours. It's sort of like the Internet: When there's trouble, you can route around it," says Robert Poole, director of transportation studies at the Reason Foundation, a libertarian think tank in Los Angeles. "The very fact that these detours are feasible to set up reinforces how adaptable and flexible a roadway-based transportation system is."
Mass transit also provides helpful redundancy in these situations. After the 1989 earthquake, commuters experienced only minimal disruptions because they were able to switch to other modes of transportation like the BART subway system, according to a survey conducted by Elizabeth Deakin, the director of the University of California Transportation Center.
Dr. Deakin's survey did find people curtailed their nonwork travel, including a 40 percent drop in East Bay residents headed to San Francisco.
In the immediate hours after Sunday's accident, BART announced it would be adding capacity to meet the expected temporary surge in demand.
"Luckily, we have enough redundancy in both transit and highways that we'll be ready to go," says Deakin. "This is a test for how well we've learned from the Loma Prieta earthquake."
There are other advantages over the 1989 event, she says, including less widespread damage and a sharp rise in the number of people who work from home thanks to the Internet.
Indeed, the impact of the latest breakdown in the cement and steel infrastructure here has already been softened by the region's world-renowned digital networks. Local news broadcasts called up Google Earth maps on the fly to walk commuters through potential detours, and checking 511.org for traffic updates before leaving the house is already old hat for many residents.
Deakin and others noted that the Bay Area was once again fortunate in the timing of its disasters. The 1989 quake struck at a time when many people were at home watching the World Series. And a fatal truck explosion in one of Oakland's tunnels in 1982 also occurred late at night.