>replace the asphalt with gravel when it starts needing repairs

And throws up a lot of dust and needs to be continuously patched and graded for potholes and washboarding. It can also get ripped to shreds by snowplows if the ground isn't hard frozen. (And even then a lot of material can be scraped off if the snowplow operator isn't good.)

Source: Have a gravel driveway and my family has a house on a fairly long private gravel road.