Recent talk of potentially tearing down 280 and building Caltrain subway didn't just drop out of the blue. Several years of have already gone into vetting the idea.

This 2013 SPUR article provides project background and explains the opportunities that is still just as relevant as it was two years ago.

San Francisco now has another opportunity to take down a freeway while creating major transportation infrastructure improvements in an important area of the city. Currently, the stub end of Interstate 280 creates a barrier between the developing Mission Bay neighborhood and Potrero Hill.

The Real Remaining Wall on the Waterfront

When the Loma Prieta Earthquake collapsed sections of several elevated freeways 25 years ago an anti-freeway movement ramped up to remove them. The Embarcadero Freeway was already an eyesore and a traffic bottleneck, but when it was torn down the traffic disappeared even as attractions like the Giants Ballpark and the Ferry Building made the waterfront somewhere you'd go other than to buy drugs.

The Embarcadero Boulevard disperses traffic more evenly across surface intersections where the freeway created pinch-points at a handful of on and off-ramps. Meanwhile the Muni Metro and historic streetcar lines along the median carry more passengers than the 8-lane double-decker freeway ever did.

But the freeway was only torn down as far as Fourth Street, where the I-280 offramp created a new chokepoint with traffic perpetually delaying Muni trains to this day. And it doesn't get any better from there because the elevated freeway creates a barrier between the Eastern Waterfront (including the Mission Bay and Dogpatch neighborhoods) and the rest of San Francisco.

Only handful of roads connect east and west because of the Caltrain commuter rail corridor running along the surface below the freeway. Those few roads will be closing in the next decade to allow more frequent and faster Caltrain service downtown along with High-Speed Rail service.

Rather than cut off the fastest growing part of the City, San Francisco is looking to do what's always worked before: tear down that freeway. Because of the way it was built, the freeway has to come down in order to build a subway tunnel for the trains.

But why go to the expense of rebuilding a freeway that's only going to be an eyesore that creates traffic and delays Muni?

The San Francisco Planning Department today announced that it will launch the Railyard Alternatives and I-280 Boulevard Feasibility Study program.

Today's announcement is for the most preliminary of steps, determining what the feasibility options are.

The Study will include: evaluation of the technical and financial feasibility of a comprehensive transportation project that consolidates/relocates existing rail tracks underground, surfaces an existing elevated freeway, consolidates/relocates a railyard, enhances the area around the Transbay Transit Center, and creates new opportunities for neighborhood connectivity and transit-oriented development. Further, the study will look at opportunities to connect and/or consolidate the two planned stations.