There will caused many different distresses after used year by year of the pavement constructed. Such as Raveling/Weathering, Linear and or Block Cracks, Edge Cracks/Breakage, Oil/Gas Spill and so on.
For example, Alligator Cracks happen in areas that puddle and after leaving cracks to go unrepaired... water penetrates the asphalt and undermines the base weakening the asphalt. As traffic drives over the weakened asphalt it cracks further allowing more water and elements to penetrate. This is considered failing asphalt.
Pot Holes are considered failing asphalt.
Generally speaking, it is absolutely necessary to repair as soon as any distress happens on the road.
