Not only that, but underground infrastructure and surrounding buildings put a high constraint on pavement design by putting a hard limit the total thickness of the pavement: can't build too deep or you'll disrupt other infrastructure, can't build too high or the road will be higher than surrounding building entrances or sidewalks.

Interstate construction don't have such limits are typically half a meter or more, not counting foundation earthworks, which can easily double that figure. In cities where telecom networks are 60cm deep and gas and electric networks 80cm deep, you just don't have the luxury of designing a meter-thick pavement that will have a decent IRI for decades to come.