What opponents overlook is that bike lanes clarify where everyone should be and improve traffic flow. They're like a demilitarized zone in the way they separate the factions: cars, bikes, and pedestrians. Before Philadelphia established its bike lane network, conflicts among those three groups were more extreme. Motorists would tell bicyclists to get on the sidewalk. While I was biking home from work recently, a driver reprimanded me for veering into the car lane. The bike lane happened to be blocked by parked cars, a common problem. Despite his blinkered vision, I took the sentiment as a kind of progress, evidence that bike lanes are considered an integral part of the road network.