[mk3]

How falling asleep while driving is even possibility. If you feel tired stop and rest.

[viraptor]

Because you can't enforce every rule in practice. There's a chance it will creep up on up on a long drive and you don't notice. There's a chance you pass out suddenly or something else happens that prevents you from steering - same system should kick in. And finally, even if you behave perfectly, it's in your interest that the person coming from the other side does have such system.

[Swizec]

Yeah and if you need to text, stop. But people don't.