If tearing down yet another San Francisco freeway doesn't seem to be enough of undertaking, turn your attention to a new proposal that calls for the replacement of the northern spur of I-280 with a street-level "boulevard" as just one of Three Big Moves designed to entirely reimagine the City's eastern neighborhoods and the southern gateway to downtown. In the mind's eye of SPUR's "Boulevard Task Force"—as understood through a recently published report, in turn based on a proposal endorsed by the Mayor's Office back in January—the 280 will touch down onto 7th Street between 17th and Mariposa and seamlessly transition into a thoroughfare that bridges the divide between Mission Bay, Potrero Hill, SoMa, and a brand new neighborhood at 4th and King. All the while, newly-electrified Caltrain and high-speed rail cars will travel underground en route to the Transbay Transit Center.

As dramatic as it seems, the partial demolition of I-280 would be San Francisco's third freeway-to-boulevard conversion, following in the footsteps of the Embarcadero and Central Freeways' removal in the wake of the 1989 Loma Prieta earthquake. In this case, rather than natural disaster, the momentum comes from the confluence of several massive infrastructure projects: the electrification of Caltrain; the extension of Caltrain to the Transbay Transit Center (aka the "Downtown Extension Project" or DXP); the eagerly-anticipated high speed rail line, and the proposed development of Caltrain's railyard.

The existing infrastructure—the freeway and railyard—creates a 1.2 mile barrier that slices through the eastern neighborhoods and consumes 37 acres of valuable land. The Three Big Moves aim to weave the new infrastructure together into an urban design that restores the connections between existing land uses and maximizes development opportunities and livability in an area San Francisco that is ripe for densification.

Haters note that, while the transformation of the Embarcadero may well be the best thing that ever happened to San Francisco's waterfront, Octavia Boulevard—which replaced the Central Freeway—has created intractable traffic problems extending a half mile out from the on/off ramps at all hours. In an interview on KQED's Forum earlier this year, Planning Director John Rahaim was cautiously optimistic about the 280 alternative, suggesting that cars would ideally disperse at 16th street rather than concentrating along the new Boulevard, but emphasizing that the City is still a couple years away from knowing whether this Big Move is actually a good idea when it comes to traffic flow.

Realizing the Boulevard (Big Move #2) depends on the success of Big Move #1: putting Caltrain and the high-speed rail underground. The alignment of these rail lines is still being explored, but ultimately—according to the Mayor's transportation policy director, Gillian Gillett—either the streets or the rail lines need to be below grade. Currently high speed rail studies show 16th Street and Mission Bay Street passing underneath the rail line, making those connections even more difficult and unpleasant for pedestrians than they are right now.

The plan endorsed by SPUR and the Mayor's Office, on the other hand, calls for the tracks to be depressed to allow for the surface Boulevard that provides an aesthetic streetscape, facilitates neighborhood connections, and creates less noise. Ideally, the underground tracks could also allow for a train route more direct and efficient than the current alignment.

Finally, Big Move #3 focuses on redeveloping Caltrain's massive Railyard at 4th and King. The SF Planning Department has had its eye on the 30-acre site since 2010 and tapped Economics and Planning Systems to do an in-depth study of its financial value and development potential. The report essentially concludes that—since the railyard is located in red-hot growth area and therefore worth a whole lot of money and San Francisco needs to provide more housing and office space in that neighborhood to meet not only existing local demand but regional smart growth mandates—Caltrain should find a new parking lot for its idle trains and California High Speed Rail planners should rethink their plans to prioritize building on that land stat. As an incentive, the money generated by creating a transit-oriented residential and mixed-use development at the railyard could help finance the DXP and other partially-funded projects.

Momentum for the big vision is accruing steadily, but there is still a lot of studying to be done. According to SPUR, roughly $2M of studies will be required. To name a handful: Caltrain is assessing whether the Big Move #1 will stall the planned electrification due to be completed by 2019 and exploring alternatives to the railyard site for its projected storage needs; the CA High-Speed Rail Authority is doing a broad study of the implications of the 280 demolition, and planners from the MTC and the city will be doing extensive traffic analysis for the whole project. It turns out that even though there are just Three Big Moves, the numerous associated stakeholders, governing bodies, studies and documentation make realizing this vision a daunting prospect. But such is the nature of city-making and remaking and—to quote architect Daniel Burnham—only a big plan has the "magic to stir men's blood" and "once recorded will never die, but long after we are gone will be a living thing, asserting itself with ever-growing insistency."

If you're already sold on the mega-project and think you know how to make it sing, consider throwing your hat in the ring of a design competition aimed at reimagining the spaces to be opened up by removing the 280 spur along the proposed boulevard. The Center for Architecture + Design and seedfund, alongside a healthy pack of partners that includes SPUR and the SF Planning Department, are offering up $10K in prize money for the best designs. Who knows? You might be laying the groundwork for SF's newest microhood, soon to have an irritating portmanteau no doubt. MishBaySoMaPot anyone? - Laura Tepper

· Taking Down a Freeway to Reconnect a Neighborhood [SPUR]

· 280 Freeway Design Competition [Center for Architecture and Design]

· 4th and King Street Railyards Final Summary Memo [ SF Planning]

· Should SF Tear Down Part of 280? [KQED Forum radio segment]