The distances are not a problem if the right means of transport is in place.
First of all, with the US speed limit of 55 mph (and even the 70 mph, or is it 75 mph), on the best freeways, large distances take a long time by car or by bus, and the difference between buses and cars does not matter much in way of speed.
Of course, I agree that with large suburbs in place, the question is how to design a working public transit system. However, consider a combination of high speed trains (like Shinkansen, ICE and TGV) for long distance travel, plus a sufficient number of subways, regional trains, etc. for short-to-medium-distance travel. Smaller cities and remote areas would have to be connected by bus.
As for the POD you definitely need something to happen to US gas prices. So make the oil crisis far worse by establishing some very fundamentalist anti-Western governments in Saudi-Arabia, Iran, Iraq and Kuwait. Then have the US government introduce a fuel tax similar to that in Germany, say, because fuel reserves are low and this precious commodity must be conserved. Maybe even introduce fuel rationing.