alt Hacker NewsNormally your top speed is not really very fast as the pedals are fixed to the wheel, so you get one rotation per pedal (extremely low gear) and slowing down is not often necessary.
You can overtake bicycles easily going uphill, but downhill is hard on your knees!
I find that going downhill also uses different muscles than riding a bike or walking. I got really sore when I first started riding!