I lived in Warwickshire until recently and they have introduced 50mph quite widely. I have mixed views about it. I don't think it will reduce accidents by many, as those who drive/ride recklessly are probably ignoring the 60mph limit anyway.
From a different perspective, reducing average speed will improve fuel economy and reduce carbon emissions. For an oil dependent country, as Tesco says, 'every little helps' in the battle to reduce our collective carbon footprint. It also improves the odds for the blackbirds and other hedge related wildlife. When I'm riding at 50 there seem to be fewer near misses with swooping birds. I've also come across a few monkjack deer on the verges. If you hit one, there's a good chance you won't walk away.
There are some fantastic stretches of A road. The Fosse Way was a favourite of mine, with fantastic sweeping curves, undulations and fast straights. I've known a couple of bikers killed, as I'm sure we all have. A farm tractor turning right killed one, the other in a head on taking a left hander slightly wide as the car coming round cut the apex.
I'm probably getting old and slow, which is why I got rid of the VTR and bought a Bonnie. Still tempted by a Daytona 675 though