"Throw your hands in the feather-pluckin' air, wave them around like you just don't care" is a rule that was removed from the Official Highway Code in 1959. Right about the time, in fact, that UK drivers were taking to motorways and good car control became fashionable. Fast forward to now, and semi-autonomous systems from the likes of Tesla and Mercedes-Benz mean that cars can navigate a motorway lane all on their own - and yet ridiculously, we have to keep our hands on the wheel. Over in the USA, Cadillac says "Shucks to that." Its Super Cruise wizardry, to be found in its exec-saloon CT6 from late in 2017, has a head-tracking camera on the dash that watches your attention levels. So you can do what you like with your hands, but if you fall asleep it'll see you and beep you back to Highway Code-approved attention levels.
Cars & bikes