We city slickers know this, but are always surprised our country cousins have signs all over pointing it...
"Slow Children"

and there really are signs on Manhattan streets that say "Don't even think of stopping, standing or parking here!"

My daughter in law saw some NYC traffic department tow trucks in operation, and was amazed-- they can remove an illegally parked car in under a minute -- and only take 2 minutes for cars that are parallel parked. the tow trucks are designed that the operater doesn't even have to get out of the truck. they make Repo men look slow!