Driving along an urban dual carriageway, 50mph limit, everyone behaving nicely when Jeepy thing in front wobbles and passenger door opens. Car wobbles even more and I can see driver leaning across to close door. Wobbling stops. I gingerly pass as Jeep has now slowed to about 40mph. As I approach door flies open again, wobble, driver stretches across and door closes. I pass looking carefully.
There is a kid on the passenger seat in gales of laughter as he opens the door again. Dad is shouting and very distracted, not looking ahead, and I am past before he leans over again to close door. In my mirror I see him swerving rather than wobbling this time, Other drivers are giving him a wide berth.
Children are a danger to everyone around on the road. Back to topic, yes the signs were originally for information in case of accident.