On the N. Wales expressway from Caernarfon, Wales to Skipton, Yorkshire.

Me and my friend were the designated drivers as we had prior experience driving on the left side in New Zealand, some 16 years prior.

We had no issues, though some country side roads were very nerve-wracking narrow.

And we had to navigate around the countless number of roundabouts.
Counting the number of legs for our expected exit point.