I don't think your logic works. Cars are 10x longer, but (for example) my house is not 10x longer in all 3 dimensions.
The streets in downtown Salt Lake City were famously designed to be able to turn a horse-drawn wagon around. That width turned out to be pretty good for cars when they came - no additional scaling needed.
The streets in downtown Salt Lake City were famously designed to be able to turn a horse-drawn wagon around. That width turned out to be pretty good for cars when they came - no additional scaling needed.