Why should you never use the trailer's spring parking brakes as your primary way to slow down while driving at speed?

Pick an answer

1. Spring brakes are the recommended method for all normal stops
2. They provide identical stopping performance to the service brakes at any speed, when spring brakes actually apply with full force all at once instead of gradually
3. They are designed for holding a stopped vehicle, and using them at speed can cause a sudden, uncontrolled stop
4. They are only usable while the vehicle is already parked, never at driving speed

Correct!

Not quite. The correct answer is highlighted.