> Speed limits in North America were lowered to save fuel during the oil shortages in the latter half of the 20th century and subsequently were never raised. I

> Speed limits in North America were lowered to save fuel during the oil shortages in the latter half of the 20th century and subsequently were never raised. I can't speak to Canada, but they were certainly raised afterwards in much of the U.S. The only exceptions I've come across are roads and highways that are frequently congested (e.g. in DC) or local municipalities doing the speed trap thing. But most states raised to at least 65 mph from 55.