problem isn't zoning but design regulations. A lot of street design is dictated by being able to fire engine equipment in and turned around. Hence no new alleys are being built.
The "residential" road that I live on is (and most in the area are) 45 ft wide, with 2.5' sidewalks. The Hummer H1 is an incredible 7.2 feet wide, meaning you could fit six full-size hummers side-by-side down this road. Add in the mandatory front 30ft setback and you have a sight line that is around 110 feet wide.
People are expected to go up to 30 mph here. They don't.
We could build fire equipment to fit narrower streets.