Might not be too late. Car culture has heavily influenced planning in the States. If the focus shifted to public transportation maybe the planning would follow, though it'd take a lot of time to change
Especially if you consider, car-centric development is bankrupting many smaller US cities. There’s a strong economic case for promoting dense, mid-rise, mixed-use development: it brings in much more in property taxes relative to the cost of city services required.
Simply put, every foot of road or pipe or power cable serves far more people (and economic activity) with dense development.