IMO self driving cars may be the (very expensive) solution:
-Bad drivers who become uninsurable become required to purchase expensive self driving vehicles, or give up car ownership entirely.
-Big clown car SUV's already have stiff financial penalties for those dumb enough to purchase them without a need. I'm against lumping all vehicles in the category as small light SUV's like the CR-V, which aren't clown cars, which don't take up excess parking, which have carbon emissions only slightly higher than many coupes and sedans, are not nearly as bad.
-In cities, more public transit is required, and large cities need to have reduced growth as this is what will fuel the growth and improvement of mid sized cities as people move there. In US cities especially, expanding public transit needs to come with expanding the presence of police and tolerating less chaos and disorder. Public transit in the US needs to become clean, safe, and not a haven for the homeless. Public transit everywhere else in the world does not carry this stigma, and as a result, the expansion of it is rarely opposed. But in the US, it carries the very real perception of increasing crime, and thus is opposed at every turn. And statistically, crime does go up when public transit serves an area in this country. We need to look at why that is so that it can expand to meet the needs of today's cities.