Can totally sympathise. My DD also has serious road safety issues.
She used to be fine - really aware-but over the last few months she has made some major misjudgments when she's been out with us that I've torn strips off her for. I've no idea what she's like when she's out with her friends - I'm trying not to let her walk anywhere at the moment on her own until I'm a bit more confident that she won't get run over.
I have devised a route for her to get to secondary school that uses mostly zebra crossings with only a couple of other smallish roads to cross. Not sure how I will enforce her using this route though - especially if she wants to walk home with friends.
I'm going to do some road safety 'training' with her over the summer holidays but if that doesn't work I may resort to driving her to begin with.
I have explained to my DD that she must use her own judgement and not trust that of her friends (she ran across the road in front of a car to join her friend on the other side of the road on the way to school recently - only a small road though and the car was actually far enough away but it was still a silly thing to do) especially as she has eyesight/spacial awareness issues.
Love to hear what other people have done to deal with this.
tco - you posted while I was writing my monologue - I think your suggestion might be a good one. My DD doesn't seem to understand that you can't afford to make even one mistake..