What if cities had no sidewalks and everyone walked on the road? Or, for urban recreation, they walked on a few scenic trails? What if the occasional street had a three-foot-wide "walking lane" painted on the asphalt, between the moving cars and the parked ones?
Well, for starters, no one would walk much. A hardy few might brave the streets, but most would stop at "walk?! in traffic?!"
Fortunately, this car-head vision is fiction for most pedestrians, but it's not far from nonfiction for bicyclists. Regular bikers are those too brave or foolish to be dissuaded by the prospect of playing chicken with two-ton behemoths. Other, less-ardent cyclists stick to bike paths; they ride for exercise, not transportation. Bike lanes, in communities where they exist, are simply painted beside the horsepower lanes.
People react reasonably: "bike?! in traffic?!" And they don't. "It's not safe" is what the overwhelming majority say when asked why they bike so little. (As it turns out, it's safer than most assume -- on which, more another day.)
So what would cities look like if we provided the infrastructure for safe cycling? What does "bike friendly" actually look like?