I ride through the absolutely horrible streets of midtown Manhattan and I have gone down a couple times, one time where I was digging dirt out of my palms. But really, I think if you are smart about your speed and keep your eyes on the road, the danger is mitigated somewhat. One thing I always do is keep the motors engaged at all times, which is less energy efficient, but at least lets me know if my remote has lost connection with my board since you can feel the sensation of the motors disengaging power.
It's not common at all. I always keep the belt engaged because it also keeps the deceleration constant, and I do not know how to brake normally -- so the brakes are the only thing that will save my ass if a car jets out in front. Never had the remote cut off except the one time I forgot to charge the remote. But the beeping about 10 times before it cut off was ample warning. I have never really fell in love with a product before as much as the boosted board - and this is coming from someone who had zero skateboard/longboard experience. Maybe I'm a natural, or maybe it's just dumb simple to learn. I still can't cut corners very well and have problems figuring out the right tightness for my trucks, but that's my hangups, the board is still a great piece of engineering.
