The U.S. just does not have the necessary resources because it would look like a large memory model whereas a small memory model could easily have global variables and be completely efficient. The U.S. has many more cities than many other countries. To have a city that is populated by no more than 30 people to have public transportation is just blatantly wrong. "And, of course, it's these short trips for which the '5.6 litre gas-guzzlers' are particularly inefficient!!" This problem occurs because Americans are unwilling to use human powered vehicles. Why would a bus be needed if no one rides the bus? Because the bus takes too long to get where you need to go and because there are not enough routes to get you where you need to go efficiently. In a small model, public transportation makes sense, but in a large model it does not. I would not make an entire program have global variables if it was a large memory model. The U.S. operates as efficiently as it possibly can given the land mass. There is not too much room for improvement, otherwise wouldn't you think that it would have been done already?