What makes a good bike lane?

I came across this website called Streetsblog today that shows  examples of good bike lanes.  If you go to the link you will notice that they are all separated from traffic by some sort of divider.  This is often ignored in America; here a bike lane is just an extra small lane that is set aside for cyclists.  The idea is that a bicycle belongs in the street just like any other vehicle, and that extra accommodations (beyond a slower lane) for bicycles are simply unnecessary.  Madison is a perfect example of this; most bike lanes here are either in the parking lane or between the normal lanes of traffic and the bus lane.  This makes one feel extremely vulnerable most of the time; either you are dodging parked cars (and their doors) or have cars and buses motoring past you on either side.

There is a feeling among many cyclists that even though there may be bike lanes on some main streets, the unsepereated traffic makes it far too dangerous to actually use the lanes.  And this is considered to be an adequate bicycle accomodation by those who design streets.  It seems to me that if we actually want to make cycling a practical method of transportation we need to build infastructure that makes it safe.  Simply drawing lines doesn’t do that.  The lines only accomodate the cars by getting the slower bicycles out of the way.