Well, they are for cars. So play at your own risk.
I played in the streets and rode my bike every summer day (still do just not as much). But I also knew that 2000lbs of steel traveling at 30mph is not going to stop for me so my life was in my hands and I needed to be vigilant.
That's a mistake, I think. They are for traffic and that includes kids, adult pedestrians, people on bikes, people with dogs, mopeds, and yes, cars. And as the driver of one of those you have a responsibility towards all those lesser protected members of society.
