I think you are getting confused with "mapping" and "checking".

Mine was mapped on an engine dyno, and then all the low speed / cruising maps were done on the road (on the way to and from Bruntingthorpe), where the fuel / ignition and boost maps were checked and adjusted as necessary whilst running absolutely flat out in fifth gear. Now considering the speeds reached (175mph), I certainly would NOT want to being checking that out on the road .