Though I have worked with some autistic children in a school setting, I don't have an extensive amount of experience and only limited knowledge of autism. I wasn't sure if the sign was because some children with autism tend to get caught up in their own world and wander more or something of the like. I mean, any child could dart out into traffic. Though it is good that more people are learning about and becoming aware of autism - wouldn't a "children at play" sign have sufficed?