> Of course, petrol costs a lot more in Germany than in the US. In practice, that tends to limit driving much more

Not really. People that drive a lot or like to save money just buy more fuel efficient cars - whenever I read about fuel efficiency of US cars (and bother to convert gallons and miles to units I understand) I am shocked how super inefficient many vehicles on the US market are, especially given that speed limit - likely due to much lower petrol cost.