> Sidewalk bike lanes from a cyclists perspective are the worst implementation.

I cannot emphasize how much I disagree without this statement. When I use a bike lane on the level of the road, I have to:

• constantly watch out for inattentive people opening car doors into the bike lane;
• frequently go around cars parked in the bike lane, forcing me merge into traffic;
• fight with buses who pull into bus stops to let passengers off, forcing me to merge into traffic. As the bus and I are often traveling at about the same average speed, this leads to a game of leap-frog, where they zoom past me only to pull over at the next bus stop.
• watch for inattentive people going to and from their cars, as they step into the bike lane without looking.

Yes, pedestrians sometimes obstruct bike lanes on the level of sidewalks, but I find this much less dangerous and less irritating than the above. In Cambridge, riding down Western Ave is just a delight compared to riding on Mass Ave, even after the massive improvements they've made to the bike lanes on the latter.