[berkut]

I'm pretty certain the road signs were replaced after WW2 - it's not like there's no road signs any more.

This is the opposite of my experience as well - I've driven in many countries (currently live in NZ), and despite its quirks (not saying it's perfect), I've found using UK road numbers for directions very easy in general compared to other countries that have highways that re-use road numbers in multiple states or something, which has at times caused confusion.