Prove it.
Fine. Which needs to stick out more into on-coming traffic when checking to see if it is safe to overtake in Poland: a standard LHD vehicle or a RHD vehicle fitted with a video camera on the outside edge of the left-hand wing mirror and a flipdown LCD screen in the sunvisor?
Harry:First, driving on the left is safer: Prove it.
Fine. "Research in 1969 by J. J. Leeming showed countries driving on the left have a lower collision rate than countries driving on the right. It has been suggested this is partly because humans are more commonly right-eye dominant than left-eye dominant.[24][25][26] In left-hand traffic, the predominantly better-performing right eye is used to monitor oncoming traffic and the driver's wing mirror. In right-hand traffic, oncoming traffic and the driver's wing mirror are handled by the predominantly weaker left eye. In addition, it has been argued that left sided driving is safer for elderly people given the likelihood of them having visual attention deficits on the left side and the need at intersections to watch out for vehicles approaching on the near-side lane.[27] Furthermore, in a RHD car, the driver has his right (i.e. dominant) hand on the steering wheel at all times and use his left hand to change gear.
Cyclists and horse riders[28] typically mount from the left hand side. This places them on the kerb when driving on the left."
en.wikipedia.org/wiki/Right-_and_left-hand_traffic#Safety_factors
That would be the right thing to do (and it is feasible, Norway did it in the 50s or 60s, I can't remember), but one of the charms of Britain (for Ireland, I don't know..) is that it does things differently from the rest of Europe..
A lot of EU countries have changed over: Czechoslovakia, Austria and Hungary all changed over after being occupied by the Nazis. Bit worrying for Sean that he shares the same views with the Nazis on a couple of subjects!