This wont be anything to do with planning, or the council, as it seems to be a straightforward property issue
If the deeds don't' specify a dimension, or an actual use (eg footway, bridleway, vehicular etc) then the width can be interpreted.
However, if there is established use by cars, which can be seen just by looking at the rest of the drive, then that will be the width - ie enough for a car to drive down
Rights of ways are just passage, and do not include turning or manoeuvring etc
You can fence the land off, or just put a row of daffodils there to mark the driveway and your own private land. Then any damage to you land is a tresspass