Heheh, I feel like I'm making my point poorly :) The driver is in a 3000 pound vehicle capable of accelerating from 5 MPH to 60 MPH in a couple of seconds. The biker is an unprotected human capable of traveling 10, maybe 20 MPH as an absolute maximum. My point is that these two objects cannot share traffic on a US street that is designed for cars traveling 30 MPH for more than a brief period of time.

If they do share that traffic lane, bad things will happen. Humans will make bad decisions, because humans are dumb and fallible. My point is that situation should not occur in the first place. It's engineered to fail, and sure enough, it does.

Better to leave the car out of it then. After all, Boston's narrow winding streets aren't designed to accomodate them.

The only people that will make bad decisions are the aggressive angry drivers, which should be removed from the road ways for the benefit of all innocent people.

Well, that's obviously not true. I've seen bicyclists.

Maybe speed limits should be reduced to 25 MPH within cities (a la NYC).

20mph is a nice magic number for speed limits. That's the maximum speed where a collision with a pedestrian is highly unlikely to be fatal.