Well, an average over 12 and a minimum of 12 are different things, plus they may be talking about the US only - different countries may have different strategies. But I agree on popular routes and high population areas 12 really should be the minimum - with Rugby, Hopwood Park, South Mimms and Exeter all being much larger - central belt Scotland could do with some more capacity. I also agree with the point about rural areas - most of Scotland outside of the central belt and the M74 is a desert when it comes to superchargers (and third party equivalents) - it would make a lot of sense to have some 4-6 stall sites at various extremities on tourist routes, in the Highlands, ferry terminals to the islands, the South-West, and Borders.