It's not the study. It's what the safety thugs are going to do with it that's the worry.
But who in 1960 would have believed that you could be arrested in several cities in 2007 for smoking a cigarette in your own back yard.It'll never happen. Just look at old cars, they don't meet emissions they're relatively unsave and could be banned in the same way.
Only problem is it would never really go through with out the government offering to replace them with a car that could be still be used for transportation - same with motorcycles.
I mean think of all the people that use motorcycles as transportation it would cost a lot to replace those. Not to mention all the dealerships that would have to close down.