Not a great example, the early days of cars saw both cars on the road AND safety warnings to err on the side of the horses while cars were bedded in.

https://en.wikipedia.org/wiki/Red_flag_traffic_laws

No, they would have had to wait till stop signs were introduced at smaller sections and stop lights at all major, except those for whom traffic circles could be created.

Roads would have to be striped properly and there would have been an international Consortium to determine whether people should drive on the left or the right hand side of the road. That would still be ongoing of course

Meanwhile, in reality, the introduction of cars did actually come with initial limitations.

In hindsight not nearly enough limitations and caution, slower growth would have ideally come with better recognition of the risks and better appraochesto minimising externalities.

I really struggle to think why restricting car development in light of environmental concerns would have been a bad thing. Much milder climate change? Better-designed, more pleasant cities? No leaded gasoline? Sure, economic growth would have been held back a couple of decades, but no one would have really noticed.

What makes you think anything would have come of it? They wouldn't have known the dangers of leaded gasoline for another 70 years, for example.

When you say hold back economic growth, what you're really talking about is people dying from starvation.

> When you say hold back economic growth, what you're really talking about is people dying from starvation

Population expanded to eat the post WWII agricultural boom - economic growth apparently leads to more mouths at risk of starving.

Why not let populations match economic activity rather than create greater and greater problems with endless expansion and greater resource demands.

ie. You're taking as gospel something that needn't be.