I've ridden a bicycle on Fairmount Avenue many times in its pre-bike-lane state. I've also driven a car on Fairmount Avenue, and been a pedestrian in that area. All of these experiences led me to the same conclusion: Fairmount Avenue has needed bike lanes for a long time. The street is much wider than necessary for its two travel lanes and two parking lanes, allowing motorists to speed more than they do on narrower Philly streets. Bicyclists perceive the road to be a major artery (like Broad Street) and illegally ride on the sidewalk at a higher-than-average rate, endangering pedestrians. It's a pretty classic example of a road built to accommodate cars rather than human beings. In such a chaotic situation, a set of basic bike lanes is a great first step toward bringing order to a street, simply by giving everyone their own space.