One interesting part of the asphalt process that you might not be aware of happens before any asphalt is laid. It’s called asphalt milling.
What is asphalt milling?
Milling is the process of removing the top layer of asphalt to a specified and even depth without disturbing the underlying subbase. This allows new asphalt to be laid down without increasing the height of the road and saves you time if the subbase doesn't need to be fixed. Thanks to the milling process curbs, drainage and other existing structures remain undisturbed.