<And the internal combustion engine "drove" the structure of society, allowing people to live a long ways from where they work, a long ways from relatives, and so on. For another power source to be viable it would have to live in the internal combustion world, and that could be tough.

Had internal combustion not been viable societies may not have developed the sprawl.



Government-subsidized roads and interstates may have also played a role in this. The internal combustion engine will phase itself out when the time is right. Making sure that oil prices are allowed to rise as supplies become harder to find is a critical part of this process.

If you took it away, or severely limited emissions, or rewarded less emissions, or penalized higher emissions, another way to power vehicles would come along, and society would change a bit, I think.

So which authority gets to "take it away?" and under what pretense? We are already rewarding low emissions and penalizing high ones. Just as one example, electric cars get to use the diamond lane in many areas here. Too bad they don't have the range to appreciate it.

Imagine what life would be like if everyone had to use muscle power or take mass transportation. I think people would structure their lives differently.

You don't have to imagine it. Check out those many third-world societies where people are using muscle power, in the fields as well as for transportation, or are forced to use mass tranportation because nothing else is affordable to the average citizen (the leaders have limos and private jets). I myself don't find such places very attractive, but then that's just me.