After the devastating 1989 Loma Prieta earthquake, San Francisco tore down roughly six miles of elevated freeway, clearing room and sky and letting the Embarcadero, Ferry Building, and Hayes Valley flourish.
Now, some city and state officials are floating the idea of more removal: the elevated 1.5 mile Central Freeway, which runs east-west from Market Street to the confluence of Interstate 80 and Highway 101.
Until this long-shot dream comes to fruition, however, SF faces a more immediate reality. The streets and chaotic intersections that run under the Central Freeway are some of our busiest, most dangerous, and most important for crosstown travel — and they need to be fixed. Changes are coming; a safety upgrade is due to begin later this year or early 2024.
This week, the San Francisco Municipal Transportation Agency board voted for a one-year experiment with new (and controversial) bike lanes on Valencia Street, and more details emerged about the city’s expanding bike-friendly street network.
Less heralded, but no less important, is what happens below the Central Freeway. The heart of it — the major artery, really — is 13th Street.
This six-lane road conveys traffic to, from, and around the Mission, Mission Bay, downtown, South of Market, the Castro, and western neighborhoods — not to mention on and off I-80 and 101.
A 2019 study of five intersections around I-80 in SF found that the massive intersection where Mission, Otis, Duboce, and 13th streets meet had the highest total traffic volume of the five at 9,093 vehicles during peak travel times. It has also been the second most dangerous intersection in the city since 2018.
Drivers cutting through might easily forget this is also a neighborhood, with restaurants, shopping, a food truck lot, a skate park, a dog park, and a living alley. Many people call the street home, including those who reside in the Division Circle Navigation Center and in encampments that line the thoroughfare.
City traffic engineers working on a 13th Street safety plan reported recently that 99 injury collisions have occurred here over the last five years. Pedestrians and bikers accounted for a third of the injuries.
Jackie Chu, who works at Rainbow Grocery, avoids using 13th Street when she bikes there. “People drive too fast, and the bike lanes are not that protected,” she says.
The three blocks getting a safety upgrade — one of the blocks is actually the eastern end of Duboce Avenue — are part of the high-injury network, the 12 percent of city streets where 68 percent of crashes happen. Many safety projects on the network have used “quick build” methods: cheaper, faster tools, like plastic barriers and paint on pavement.
But the 13th Street project requires bigger-ticket remedies such as upgraded traffic signals and concrete to make wider sidewalks. Roughly 70 percent of the $9.3 million project will be paid by state grants, according to SFMTA engineer and project leader Paul Stanis. (SFMTA declined to provide a further breakdown of the costs.)
The project will be a balancing act, perhaps the most difficult among the many upgrades across the city, to make people like Chu safer yet maintain the flow for drivers, whether they’re freeway commuters, organic bulk shoppers at Rainbow, or contractors in pickup trucks hauling Sheetrock away from Discount Builders Supply, a construction supply hub.
At an SFMTA board meeting last fall, the agency’s director for livable streets, Jamie Parks, warned of the difficulty. “Every intersection is large and complicated,” Parks said. ”There’s no quick build solution here.”
Short of tearing down the mass of cement and metal hovering over it, the project could be one of the city’s stiffest tests of its dual commitments to creating a 21st-century, climate-friendly city and meeting its Vision Zero goals.
Very dangerous
A stroll along 13th Street under the freeway isn’t particularly pleasant, but it’s educational. You can still see the seismic retrofitting installed after Loma Prieta shook the city. The metal columns and supports straddle the roadway, and two large, complex intersections directly connect to the freeway with an onramp and offramp, ranking them among the 10 most dangerous in SF, according to TransBASE, a dataset that combines information from DPH, SFPD, and SFMTA.
All these elements require compromise in the new design, according to SFMTA’s Stanis: “One of the biggest challenges in designing this project is balancing the needs of various road users, providing high-quality safety improvements for people on foot or bike while maintaining freeway access that’s important for regional travel and connectivity.”
Perhaps the biggest challenge in the entire project is where five lanes of Duboce turn into 13th. It includes Mission, and one-way Otis carries cars south into the confluence. But wait, there’s more: The Central Freeway off-ramp spills cars either onto Mission or across to Duboce.
To cross it all on foot requires, it seems, advanced math skills, patience, and a prayer that skinny pedestrian islands protect those who can’t cross in one go. “It is a very unsafe place for everyone right now,” says street safety advocate Luke Bornheimer.
The major changes at the intersection and for the rest of the project can be sorted into four main groups. (Details are subject to change, as the design is ongoing.)
Wider sidewalks: Here’s where a “quick build” won’t cut it. The city must pour concrete and reshape sidewalks, including corner “bulb-outs” that shorten the crossing for pedestrians. The two freeway ramps are crucial spots. At the 101 off ramp at Mission, they also plan to have a curb extension — an island that is in the middle of the roadway that separates bicyclists and pedestrians from traffic coming off the freeway.
Better signals: Traffic light upgrades will improve visibility and timing. For the first time, bicyclists will get dedicated signals in the east and westbound directions to allow them to travel car-free through the intersections. The new traffic signal scheme will also restrict cars from turning right on red from 13th Street to the freeway on ramp at South Van Ness as well as from Otis onto Duboce.
Protected bike lanes: The current lanes, separated from traffic by flimsy plastic posts, will gain protection from concrete medians “to the greatest extent possible,” says SFMTA engineer Stanis. They’re important to encourage crosstown biking; there are protected lanes on Valencia Street to the west and on Townsend and Division streets to the east. But the underprotected section along Duboce and 13th “remains a stubborn gap in our city’s bike network,” adds SFMTA’s Parks.
Fewer traffic lanes: To make room for better bike lanes, pedestrian islands, and safer right-turn lanes, all three blocks of the project will slim down from six lanes to four between Folsom and South Van Ness. Westbound between South Van Ness and Mission, nearly one-third of 13th will be a single lane, and eastbound traffic will have a single lane for two-thirds of the route along Duboce between Valencia and Otis. These so-called road diets always raise drivers’ hackles — it seems obvious that they’ll make congestion worse — but time and again data show the opposite is true, as SFMTA data shows on California Street.
Truck queues
Ultimately, this stretch of road must invite pedestrians, bicyclists, and motorists to travel safely while also allowing businesses that rely on driving customers to operate without major interruption.
Discount Builders Supply is right where the freeway off ramp meets Mission, and not many people arrive by bike. (For those who do, the parking lot offers charming homemade bike racks.)
Many customers arrive in large vehicles to stock up on materials early in the morning. “We see trucks lined up before we open,” says operations manager Zeke Villalobos.
Villalobos says the upcoming changes along 13th Street will not affect Discount Builders. (He had a bigger beef with the business that took over part of the alley between them and reduced the store’s parking.)
The overhaul will also make allowances for businesses like Scuderia, a Vespa dealer on Duboce between Valencia and Woodward that uses street spots for scooter display purposes.
Construction is slated to start later this year or early in 2024, which seems like a long time, but the alternative is to wait for a total teardown of the Central Freeway. In the aftermath of Loma Prieta, it took nearly 20 years for SF to raze a much shorter segment, the one that used to stretch from Market into Hayes Valley. Removing the rest of this behemoth — and the ensuing political fights — could take decades.
