0.5 miles for a road test lol never heard such a quote
i am a ford tech and we are supposed to road test every vehicle before and after any work is carried out at all including services diagnostics etc.
there are many different road tests associated to certain types of jobs that either need diagnosing or testing etc. for example if you come in and said your car ad a rattle that only happened when you went over a bump you would have to road test till you found it then took it back fixed it then road tested it to check all was well now how could you say this would take a certain mileage ??? but i agree that if you just had a routine service then as long as there was no rattles or knocks then a straight forward road test covering between 2-6 miles depending on a route or location etc would be about right .i always do at least 2 miles before and 2 miles after every standard service so i know there are no problems as we all have had the well it wasnt there before routine so i make sure i cover my ass.hope that helps mate