The city does this every Sunday in the summer in Boston on Newbury Street and it's absolutely fantastic. I swear the street feels like it doubles in foot traffic. It really feels like that's how the street should have been designed from the beginning. Sadly, people still complain all the time about parking on the most hectic shopping street in Boston and I just have absolutely no sympathy for them.
I live on this street. Honestly, it gets more foot traffic already than much of the town. There's a school and many of the kids walk home. Which is rare in Boise. Unfortunately, the highway district has turned the street into a stroad and much of the day has a ton of car traffic at decent speeds.
But I am not buying the idea that they're promoting foot traffic and busses so much as working with the three new(ish) businesses on the street to promote gentrification.