Well you can't legislate for every circumstance, such as cars pulling trailers up long hills, those b*ast*ard caravans, getting boxed in behind lorries, bad weather (define!), etc., and a minimum speed law would probably become just as much an ass as the routinely ignored maximum speed law. Unenforceable laws do not good laws make. 60 would seem to be a sensible minimum speed in good conditions and I think that the Highway Code and driving instruction should make this clear to would-be drivers. After all, you can fail your driving test for not making sufficient progress on non-motorway roads. If road conditions are good, you shouldn't be doing 22 where the limit is 30 if it means you are impeding other traffic. Advocating driving at 50 in the inside lane is just very bad advice. In the end you would just get up everybody else's noses and it wouldn't exactly help your own nerves. Nor would it it contribute to building you motorway confidence. Frightened rabbits do not get to be bolder by feeling frightened.