Of all the countries you’ve mentioned, Belgium is the most appalling, it always looks to me as if their license was handed over by a sixpack of Jupiler. It’s bad on the motorways, but absolutely beyond belief on the national roads, no respect whatsoever for lorries, instead of that, they’ll overtake you whilst being in a village and in a 50km/h zone. Cutting you off on the motorway seems to be a national sport too for them, it’s therefore always a relief if I make it in one piece to France, apart from the numpties on the BP I always find it very relaxing to drive in France.
The Italians and especially the Romans are just very creative with the space that’s available, why would you only use 3 lanes when you’ve got “enough” room left to turn it into at least 5 lanes and 6 at best 