Were I the dictator, I'd just narrow the roads to one lane plus on-street parking and replace the freed area with trees or bushes (or tram tracks). Narrowing forces cars to slow down, making pedestrians safer and allowing bicyclists better blend with the traffic. Cutting down on the lanes adds congestion which effectively removes unnecessary car travel from the city area, encouraging people to walk or pedal. I would also remove huge parking lots as they alienate pedestrians and increase car travel. Certain downtown streets or blocks could be made pedestrian-only zones.
Wouldn't this affect business travel, such as deliveries to restaurants, offices, grocery stores, etc.? I think the primary thing to cut down on is luxury travel, where walking/cycling/public transit it a reasonable alternative - and to do it without hindering business.
I don't know that it would really (it doesn't in Japan), but it seemed like a potential catch.
