San Francisco had one street block near Union Square closed off for a looong time because of construction, and they put some fake turf on it. Occasionally there would be pop-up events, like a little Christmas fair. I would deliberately walk slightly out of my way to go up that block because it meant no cars and wayyy more room to walk. I loved it and was so disappointed to see it turned into a normal street again. Si…
Three blocks north of Union Square is a tunnel that burrows under China Town/Nob Hill and emerges in North Beach. It's a pretty critical artery for locals as it flattens the route between market st and the northern coastline of the city.
There was a push to permanently close Stockton St in favor of making it pedestrian only, but as Stockton St (and the tunnel) is the (real) gateway to the heart of China Town, that movement was squashed pretty quickly.
That said, I would love to see maybe 10% of the streets north of Market street turned into pedestrian-only, or reduced to one lane, converting the parking on both sides of the street into wider sidewalks and more trees. As dense as Nob/Russian Hill is, only one lane is really needed to service most of these neighborhoods. Retailers claim they need the parking but only once in five years have I driven to a market in Nob Hill.