just got back from driving a 200+ mile run. a limiter is dangerous. at 56 on the motorway its that slow your mind starts to wander and your looking out the side window at the scenery counting sheep. at one point i was reading the paper then done the crossword.i almost went for a nap whilst i was driving. looked up and i was still pottering at 56 with many miles to go . at least at 100+ your wide awake and your mind is sharp looking for traffic police and pensioners crossing the road.