What is the primary purpose of a "Shoulder" on a highway?

The primary purpose of a "Shoulder" on a highway is for emergency stopping. Shoulders are designed as a safety feature for vehicles that may need to pull over due to mechanical failures, driver fatigue, or other emergencies. They provide a space for vehicles to safely come to a halt without obstructing the flow of traffic. This is critical in enhancing road safety, as it allows drivers to exit the main lanes of traffic in an unforeseen situation, minimizing the risk of accidents and ensuring that other vehicles can continue to move without impediment.

While shoulders may occasionally be used for other functions, such as allowing vehicles to temporarily stop for minor emergencies or breakdowns, their primary role remains in emergency scenarios, rather than as designated parking areas or acceleration zones.