Considerung a bike-friendly environment, I think it is more of a cultural change, not just adding some bike lanes. I grew up in Germany, where in most places there weren't any bike lanes and often there still aren't any today. Yet, Germany and most of Europe are bikefriendly places, where you can expect to be relatively safe (of course, there is a higher risk when being this unprotected).
Many people in the US (especially children and teenagers) don't know how to participate, act and react in traffic when driving a bike, whereas in many places in Europe children get taught very early on (we actually went to a bicycle-school in elementary school, you basically learn how to navigate through traffic, read some of the most important road signs etc and do some basic first aid training). Everyone also learns how to swim and before graduating high school you basically had three first aid trainings already, whereas in the US this kind of knowledge usually depends on your state or school even.
And of course, these children become car-drivers as well and know exactly how to react when coming into contact with cyclists. You basically create a culture of understanding if you teach people very early on.