Trees severely over growing into cul-de-sac

The house on the main road has 2 trees in the back garden that are severely over growing over the fence and over the cul-de-sac. In the Fall the leaves are beginning to block up the cul-de-sac and the residents drains. The property owner doesn't seem to care as it doesn't affect their drains or cover their cars in sap and don't see a problem. The owner out the back has to keep cutting the tree back to the fence as it's constantly overgrowing onto their driveway.