My understanding is that there are different grades of asphalt. In fact, the best asphalt is concrete. If they use highway concrete or high-grade asphalt, the roads last much longer—fewer pot holes and less wavering damage from large trucks. I see you're nodding your head, but the mike can't pick it up, so I want to make sure I get that on the record.
I think in Australia almost all the motorways are concrete now and the quality of the roadway is far superior to asphalt.