I worked on a dirt road being paved back in 1964. Lots of grave hauled in, leveled, then road graded back up and spread out again, then graded up again, over and over all summer.
Finally they got the gravel down again, sprayed oil and gravel over it. DONE!
Within a year it was breaking up.
Saw another dirt road being paved. Hot mix asphalt was used. After forty forty five years it is still good.
Concrete roads wick up water, which is in abundance here in Michigan ([singing] the beautiful state, the roads are deeper than the lakes). Around 20 years ago some geniuses tore out one of the stretches of one of the interstates, right down to nothin’, laid a new bed, then laid down asphalt, then poured the concrete over that. Worked great. I think that’s now the common practice here.