Final answer:
On a dual-lane highway with a safety island or raised median, motorists should slow to 25 mph when a school bus is stopped and proceed with caution once the bus signals are off.
Step-by-step explanation:
When traveling on a dual-lane highway, a motorist should slow to 25 mph if on the other side of a safety island or raised median, only proceed after the bus signals have been turned off, and even then keep an eye out for children or people with development disabilities. This speed adjustment is necessary to ensure the safety of individuals entering or exiting a stopped school bus, as it gives the motorist ample time to react to any unforeseen movements.