I use only "3 or 4 number" roads, as long as I can.
It's basically a similar numbering system all through Europe, so the more numbers you'll have, the smaller the roads.
Speed limits between 40 kmph / 25 mph (around villages) to max 80 kmph / 50 mph.
Hardly any traffic at all. It's like you owned the roads, most of the time.
Quite easy to find a route with paved roads, but some of them can be rough - the Scrambler version of a Trumpet is just the right tool for these roads, 19" front wheel and adequate chocks to smooth out the progress....that said, all would be doable with a Vespa too, just with even a bit less speed and more attention to the ride line.
I had to ride the last ~30 km on a road with 100 kmph / 60 mph speed limit, within normal traffic and suddenly it all felt like business. Gone was the magic of puttering lone roads... and mayby carving some of the best bits with free ride lines when visibility was good. Once again, I was reminded that for me, traveling with a bike is not about distance - it's about the quality of ride and interesting things to explore and sometimes also people to meet!
In Turku area, I found a road dedicated to a Finnish Grand Prix motorcycle champion, Jarno Saarinen. To my great disappointment, it was a short road, ment mainly for bicycling and very slow driving/riding....