Importance to proper backfilling..

These type of road damages caused during the rainy season,
The main reason I can say is during the sewer line or any other under ground utilities, the concern authority is not doing a proper back fill and compaction by layers,
During the asphalting,the contractor just spreading the asphalt without checking the back filled condition.
( The issue here is improper backfilling )

They were just filled the sand in one time ,
while rain the water entered to the loose filled area and starts to settle down.