@Crackle I said it jokingly above, but seriously............ because they are fast roads. Maybe it doesn't make sense for leisure cycling (depending on how you get your kicks), but for racing, visibility of competitors is good, visibility for competitors is good, the surface is very good, nothing to get in the way and turns which are RAB's so big you can go round them at near full tilt, FAST. I have raced on the V718 in South Cave, it is on the A63, it runs about 2 mins faster than the fastest local Cheshire 10 mile TT course and IMO it felt safer. You don't get cars squeezing past, don't have to dodge potholes, worry about gravel on the road, you can just look up the road and stamp on the pedals.