Yeah, I know it sounds like an obvious and tempting idea, reduce U.S. oil and petrol consumption to European levels and save a lot. I agree it's worth trying, but there are some problems associated with it that one has to keep in mind. Western Europe is substantially smaller than the continental United States and population density is higher and most of us are crowded into big urban areas. I've tried driving long distances across Europe in a small car and a big limosine, and believe me the limosine was preferable. America is a big place and America has enormous suburbs, with highly undeveloped mass transport systems compared to most of Western Europe. Don't get the impression I'm being crital for the sake of it. I just think the whole question is, unfortunately, very complex and requires a great deal of planning, organisation and hard choices.

As many have pointed out, the passenger-miles per gallon nearly doubles if the number of commuters per car doubles.  The saddest part of watching the gridlock every work day in any city is not just the number of gas guzzlers, but that most of them have a single occupant.

There was a time when companies provided vans and fostered commuter pools. That mind-set will return once the price/scarcity of gasoline gets critical.

The bad news is that the US is extremely profligate; the good news - at least for a while - is that we can cut back on waste without too great a hit on lifestyle.

The question is whether we will use the time these waste-cutting measures give to mitigate - as Hirsch puts it - the PO crunch.