I think it helps that Spain is getting on for twice the area of this country but only has about (?) 2/3 of the population. Everyone just has so much more space that they are generally a bit more laid back about things. Over here, I increasingly feel like a battery hen (and that's AFTER moving away from Manchester)!
I've driven a fair bit in Spain over the years and the changes there have been interesting. When Franco was still running the place it was a pretty poor country. As a kid going over there, I only ever used to see small Fiats and SEATS - the rich people had the odd Peugeot maybe.
Then Spain started to turn around after Franco and everyone seemed to discover "credit"! Suddenly, ours was the oldest crappiest (and slowest)car on the road! I also have a (pretty hard to justify) theory that their accident rates soared around about then as they got to grips with the faster cars. Since then, things have levelled out but they still have worse (at least for the time being!) accident rates than us. Mind you, if you took out all the accidents involving kids on mopeds with no helmets, maybe they wouldn't be too different. Over here, we have a lot of rain, ice and poor visibility. Over there, they have kids in T shirts on mopeds.
I know what you mean about road works too. About 15 years ago, my wife and I took a car over to the North for a wee "jolly". The roads in the North are a lot quieter than the "Costas"! There I was doing (rather a lot of speed

) along one of those roads like you see in the 'States - dead straight with telegraph poles down one side. You can see where you're going to be in half an hour (almost)! All of a sudden, with almost no warning, we ran out of tarmac - they were re-laying a couple of miles and we were just running on rolled aggregate. That gave me a bit of a brown-trouser moment!
Anyway, on the whole, I agree with you. They tend to let you get on with it there and take responsibility for your own actions. Nice idea but I don't think it'll ever catch on over here!