Under Wisconsin law, school bus drivers are required to turn on flashing amber warning lights at least 300 feet before stopping in a 45 mile per hour or greater speed zone or at least 100 feet before stopping in a less than 45 mile per hour speed zone. The amber lights will stay on, top photo, until the bus comes to a stop when the driver will turn off the amber lights and turn on the red warning lights, bottom photo. Motorists may carefully pass a school bus when the amber lights are flashing, however, when the red lights are flashing motorists are required by law to stop at least 20 feet from the bus and remain stopped until the driver turns off the flashing red warning lights.