At 25mph I believe that on a bicycle you are nearing (but not yet reaching) the limits of the equipment. Yes, I know people who have gone 60 mph on their bikes, and I've gone 40 on mine. But at that speed you cannot stop or turn quickly. A mechanical failure could be fatal, as could a pile of sand or leaves, or a bee into your eye.

Bicycles do not have power steering, power brakes, windshields or seat belts, and they make no sound. They are small and silent making them difficult to see for both those who want to avoid being hit by them and those who want to avoid hitting them.