I've enquired with a supplier of this material, and I'm awaiting a quote for supply, suitable for a runway 620 ft by 32 ft. It does come with different loading ratings from Car (occasional use) all the way to Articulated Lorries (regular use). So, just to get an idea, getting a quote suitable for "Car (regular use)".
I suppose we could work out a proper loading for it, but the price should hopefully give us a rough idea of what sort of outlay we're talking about.
Hoping to get the quote tomorrow, so I'll post in on here when I get it.
T.