I know a little bit as I own one, albeit an access track across marshland to riverside properties.
Check the deeds of the property you are looking to buy, there is a good chance that each property is required to maintain the road and the services that run under it on an equal share basis. Find out what this annual fee is and has been.
Find out what services run under the road, also try to find out who actually organises maintenance and repairs. It’s a good idea to talk with your potential neighbours to find out how often and expediently repairs and maintenance are undertaken.
Some potholes are good as they can keep traffic speeds down.