I just came back from Italy where bikes and cars get along. their streets are about as wide as one of our lanes and still everyone manages.
When things get tight, cars actually STOP or slow down until they can pass the bicyclist safely. Bicyclists on the other hand, go single file when there is traffic.

People in cars smile at bicyclists, and the other people we saw in bikes were of all ages. Imagine a world like that! it exists. Honestly, i was passed by huge trucks. It was scary, because I could have made a mistake and gone too close to the truck drivers, but the truck drivers didn't hate me for being there. That makes all the difference in the world.