That is the kind of speed it takes to get a 747 into the air on takeoff.
Say you rolled down a back window of a car and stuck your head out (not recommended) you would feel wind so strong it would max out typhoon and hurricane scales, similar to an EF4 Tornado. The skin of your face flaps like fabric and seeing and breathing is very difficult, as seen here
And that system is AWESOME and I wish some highways in the US did the same. I fear it would devolve into a regulations nightmare after bubba in his rusted dodge rattles to peices trying to break 80mph.
Flat open highway in between cities in Kansas? Go for it!
But it's kind of like the US and guns. It's a cultural ability that is statistically proven to be dangerous and can be seen as too big of a risk for even the most responsible ordinary people to enjoy, and reckless people put the whole activity in question.