Obviously there are cities in the US built before cars, and a lot of Europe was rebuilt after cars existed, so quantifying the difference would be interesting.

Obviously there are cities in the US built before cars, and a lot of Europe was rebuilt after cars existed, so quantifying the difference would be interesting. The city I live in, in the northeastern US, started with no particular plan in the 1600s, and indeed, some of the streets were too narrow for cars. In the late 1700s, a plan was laid out, whereby "the east–west streets were named for mammals while the north–south streets were named for birds". The town I was born in, was founded in the 1660s. Probably not with a plan for the next 300 years.