A safe crossing for a child (IMAGE) University of Iowa Caption Crossing roads for children can be a risky calculation, especially when the vehicles are self-driven. In a new study, University of Iowa researchers determined pre-teenage children are safest when self-driving vehicles signaled their intent to yield with a green light when they arrived at the intersection, then stopped. Credit Tim Schoon, University of Iowa Usage Restrictions There are no restrictions on use, provided full credit is given. License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.