Spanish Motorway!

I am currently in Spain, having crossed the Iberian peninsular by car and am enjoying the sun and the drive. The drive, long, long drive was fun and I'm overjoyed to tell you, though you probably don't care to know it, that there is a great new motorway between Salamanca and Avila! It saved me probably an hour, is straight as an arrow and empty. It makes me wonder though how Spain can afford to build and maintain its excellent road network when we seem to struggle to do so in the UK. We do ok in Portugal, but if you want a half decent road you have to pay the toll. There are tolls here in Spain too of course but I don't think they've thought them through. Almost all of the motorways I know in Spain that are tolled have a fine 'A' road next to them, often practically parallel. So the though is... pay and drive 15 % faster, or not.
I guess I'm just tight. Heading back soon. Vrrrrrroooooooooooooom!