Lets use New York as an example because it's iconic. The city's road network is placed within clear blocks. Now, in near future, some 50 to 100 years from now, hover cars are reality and so common that wheeled vehicles are deemed illegal to use on city roads. The hover cars are allowed to hover from five to hundred meters of the ground, they don't have to follow the roads as closely as modern wheeled cars either. The hover cars hover by using small jet thrusters - which are slightly more noisy than modern car engines. In case of malfunction, the vehicle launches a protective foam around the vehicle just before impact.
This allows the city to, well, not exactly neglect the maintenance on the roads used by cars but to use less funds on the maintenance.
So, now I'm wondering how this will shape the cities that existed before hover cars were invented. It allows more leg room for pedestrians but what else that brings to the plate? Also assume that the hover cars became common about 20 years ago and wheeled vehicles were banned from entering cities 10 years ago. However, the wheeled vehicles are still allowed to be used outside city limits. Using New York as the example, how much the city would change? Your answer doesn't have to be about New York but you can use it as an example.
This question on how anti-gravity might change cities and buildings might be close to my question but not exactly.
The question about Urban Planning in 3-Dimensions seems to focus on new cities and the cars itself, I'm more interested on the old cities and only the cities themself.