My suspicion is you could add all you want to drivers ed, and it wouldn't do much for the real world driving of teens. I have one licensed teenage driver, one with a learner's permit and one more getting all too close for comfort, as well as contact with lots of HS age drivers.

My experience is that they just don't have the mental skills necessary to process all the information around them, whether bicycle, emergency vehicle, or erratic driver of large SUV. They tend to have tunnel vision, an inability to anticipate and prioritize the likely moves of those around them, and an inadequate view of how much they need to think, see and react. I will also note that I think my oldest is a pretty decent driver, by teenage standards.

I suspect the BEST thing we could do for teenagers is require them to spend 6-12 months as vehicular cyclists (minimum of 40?50? hours of certified time on the roads) before qualifying for learner's permits for cars. On a bike in traffic, you are confronted with most of the same issues, but they come at you more slowly (from your perspective). It would also greatly increase the number of cyclists and cyclists that people care about... you know your neighbors care more about their offspring than they do about a bunch of crazy/lazy/drunkard/immigrant/hipster cyclists (add stereotypes to suit your locale).

It will never happen, but I can dream.