I think there's a lot of fervent hope from a lot of people that sprawl is doomed by expensive energy, but personally I rather expect that technology will end up "saving" it in the end, a further testament to the trend towards decentralization, not erasing it.
Sure a commute 40 miles each way will increase in cost from $5.33 to $13.33. But $8 seems hardly a concern when you are wasting 1.5 hours a day driving.
Cheap energy is certainly necessary to create sprawl, but it isn't the only thing. Rather urban areas are often downtrodden in the US. Take a look at San Francisco, a pretty nice place by big city standards; compared to its suburbs, it has worse transportation infrastructure, worse schools, more congestion, more noise, more expensive, more danger, more pollution. The benefits win out in my 20s, but I sure wouldn't want to raise a family there.
Everyone always says this, but nobody ever seems to consider the fact that the US is also a very very big country with tons of cheap land. Our population density is 83 people / sq. mi. Germany and the UK, on the other hand, are 593 and 660, respectively. Slightly more dense.
That's the biggest factor as to why we have sprawl IMO. As expensive as energy might get, it's still going to have to compete with the lure of cheap land...
Freeways in rural areas aren't that pricey. The interstate highway system cost about $500B inflation adjusted. Only about $1700/person amortized over 35 years. Or about $13M per mile.
To see how this isn't that pricey, consider the Central subway project in San Francisco which will cost $1.6B for 1.7 miles - $1900/resident
Yes, its true that most interstates are rural. Of course that is true. I'm sure that its 95% rural. That's the nature of a network that connects all of the major cities in the country. And this 95% is probably a lot less relevant to whether you decide to live in the suburbs than the much more expensive part. Of course, your edit about the cost of the SF road acknowledges this very fact.
Its also true that in dense urban areas, interstate highways make up a fraction of the roads used for commuting.
Highways that must be put through existing neighborhoods are very expensive. And that's where highways to the suburbs had to be built. Usually by forcing other people from their homes. A lot of the true costs of building roads is hidden in pollution too.
The cost to build something is not the only cost. Roads have to be maintained, snow removed and potholes filled.
All I'm saying is that growth would be much more organic and justified if those getting the benefits of sprawl paid its costs as they went, instead of receiving a subsidy that distorts things.
Can the momentum of sprawl be halted?
It's already started. That McMansion 40 miles from town has already lost half its value since 2006. What will it be worth when gas hits $10/gallon?
Cheap energy built the sprawl; expensive energy will kill it.
But things still may not play out like OP would like. In my hometown, mom and pop businesses are still being replaced by big box chains, even in town. I never thought I'd see Home Depot, Target, & Costco 3 miles from downtown. If it's too expensive to drive to the sprawl, we'll just bring the sprawl to them.