Laws like that don't stop accidents
That sort of respect isn't the result of legislation.
Laws like that, and the publicity surrounding this bill, do create an increased public awareness about bicycle safety.
Colorado has a LOT of bicyclists - perhaps the person stoppping for you was a bicyclist?
As I cross a couple of the very few road crossings on our local trail system, I am always amazed at the cars who stop for me. And, the police DO enforce that.
But, like everywhere else, we do have folks killed every year in needless accidents.