Another idea; let’s roof roads with solar panels that also act as water collecters.
Think about it; two hazzards of driving would be avoided: you wouldn’t get sun in your eyes and rain on the windscreen. Driving would be made more pleasent and safer.
Also we could harvest all of that power that falls as sunshine onto the roads; I’ve no idea how much this would come to – but at a rough guess if we roofed most of the motorways in England we’d have enough power for the whole country’s needs. Also; I for one would not want to use rainwater from a road for anything – including washing… but rainwater collected before it hits the road – well, that’s different… at least we could use it to fill reservoirs and then purify it for drinking.
Also: what is one other major by-product of road travel? – a shedload of wind! Let’s put small vertically mounted windmills at the side of roads and use some of the wind from passing cars to generate power.
We have a hell of a lot of roads on a very small island; let’s at least use the damn things for the environment instead of against it!