BOAC: regretfully there is a tendency amongst less experienced controllers to say 'vacate next right/left' to a landing aircraft, and equally regretfully their OJTI's don't correct them. I always said 'vacate next CONVENIENT left/right'.
As soon as they get their first tyre burst due to a pilot braking harshly to make the next turnoff, they change their tune, but I really think it's the training colleges' fault for not teaching them the vagaries of the system to begin with.