What's it going to take to clean up the mess that is the Hairball — the aptly nicknamed tangle of freeways, on- and off-ramps, bike bridges, and city streets at the edge of the Mission at Cesar Chavez which lately has also been home to sprawling homeless encampments. Supervisor Hillary Ronen, who represents this part of the Mission as well as the Portola District, told city officials and reporters on a recent walking tour that her "first choice" will be to put some of these roads underground. The Chronicle is quick to note that this idea may be "illusory," and County Transportation Authority chief Tilly Chang is quick to say that this "could take decades and cost billions of dollars," not to mention the permission of Caltrans, which owns the freeways.

The Hairball has been in the news this year since bicyclists began making a stink about how difficult it's been for them to navigate the bike paths that snake through the Hairball because of all the tents and shopping carts that have sprung up there.

Homeless department head Jeff Kositsky has been charged by Ronen with setting up a new temporary Navigation Center somewhere closer to here, though there already is a new 120-bed Navigation Center nearby, at South Van Ness and Cesar Chavez, which the Chronicle reported was already having an immediate impact on the neighborhood in July. Obviously not enough of an impact on the Hairball.

"Elevated freeways are a design that’s no longer chic," said Chris Cassidy of the SF Bicycle Coalition, and Ronen echoed that by suggesting that poor design had resulted in the Portola neighborhood becoming "literally an island surrounded by freeway."

But would an infrastructure project like this ever move forward given how much it would cost? The other thing to consider is how often the underpass of Cesar Chavez, where the roadway dips below all those freeways and ramps, floods in a heavy rain. Any tunneling plan would need to take that into account too.