marjaerwin

I wish "some" bikers understood this simple analogy: cars are to bikes as bikes are to pedestrians.

http://boingboing.net/2012/09/26/cyclists-are-safe-and-courteou.html#comment-663529286

It's sometimes a good analogy, but it's not a perfect one.

Someone on foot - maybe 120 lbs - maybe 5 mph walking.

Someone on a bike - maybe 150 lbs - maybe 10 mph on the sidewalk, less around pedestrians, maybe 20 mph on the roads.

Someone in a car - maybe 2,000 lbs - maybe 50 mph on the roads.

So if the bicyclist hasn't slowed down for pedestrians, the bicyclist on the sidewalk has 5 times the kinetic energy of the pedestrian on the sidewalk. Someone biking that fast down the sidewalk is a bit more dangerous than someone sprinting down the sidewalk, because it's harder to stop and harder to turn aside.

Now if the bicyclist is on an open well-maintained trail and reaches road speeds, the bicyclist on the trail has 20 times the kinetic energy of the pedestrian on the trail. Someone biking on the trail can be much more dangerous, and has to be careful about visibility and braking distance and so on.

But the driver has more than 80 times the kinetic energy of the bicyclist on the road, and more than 1,600 times the kinetic energy of the pedestrian crossing the street.

And yes, half of you live places where's it's illegal to bike on the sidewalk, while half of you live places where it's either illegal or practically impossible to bike on the road [due to road planning issues, left-turn lights which don't respond to anything under a certain weight, or being sideswiped or rammed or right-hooked by drivers].