Oh, I've done it before. Biking to work was my primary method of transportation when I was in the bay area. By American standards, my route was pretty decent, which means that by any sane, objective standard it was trash. I got hit by cars twice the last year before I moved to Germany. Once I had my son on my bike, that was especially fun.

I was willing to take some risk, but expecting the average person to is unreasonable. Getting around shouldn't involve serious risk to your person. We'd never accept using "painted walk lanes" everywhere, and yet that standard is considered "pretty good" for biking. It's absurd.