Final answer:
An orange-colored triangular-shaped sign on the back of a vehicle is a safety symbol indicating a slow-moving vehicle, usually traveling under 25 mph, and is used to alert others to exercise caution.
Step-by-step explanation:
An orange-colored triangular-shaped sign on the back of a vehicle typically indicates that the vehicle is a slow-moving one, often operating at speeds less than 25 miles per hour. This type of signage is widely recognized as a safety sign and is used to alert pedestrians and other motorists to exercise caution when approaching. The use of the bright orange color is intentional, as it ensures high visibility under different light conditions and informs others on the road to slow down and pass with care.