What is the placement requirement for warning devices on divided highways when lights are required?

The correct placement requirement for warning devices on divided highways when lights are required is one at 10 feet from the vehicle, another at 100 feet, and a third at 200 feet from the vehicle. This specific spacing is designed to provide adequate warning to other drivers in order to ensure their safety and to lessen the likelihood of accidents in the event of a vehicle breakdown or emergency stop.

By placing one device at 10 feet, it ensures that vehicles approaching from behind can see the warning device very close to the stopped vehicle, informing them of the hazard ahead. The device at 100 feet provides a secondary warning at a greater distance, allowing for ample reaction time for drivers to safely maneuver around the obstruction. Lastly, the device at 200 feet serves as a further precaution, increasing visibility and providing enough warning for vehicles traveling at higher speeds.

This strategy is especially critical on divided highways where traffic flows at higher speeds compared to other road types. The other options suggest distances that do not align with the safety protocols established for such environments, leading to potentially inadequate warnings for approaching traffic.