It's not a winner-take-all contest. First, the roads can be shared. Second, every biker is potentially one less car on the road, thus reducing traffic congestion. This is a benefit for auto users. Further, given that biking is a more efficient use of scarce public roadways in its ability to transport more people per hour over short distances, it punches above its weight.

The only serious counter argument against bike lanes is that dedicated bus lanes would be even better if a hard choice must be made between the two.