Which scenario would typically trigger the air brake 'Q' endorsement during a road test?

• A. Class 1 license with a single motor vehicle
• B. Class 2 license with a vehicle
• C. Class 3 license with a single motor vehicle with three axels
• D. Class 3 license with a single motor vehicle with two axels

Answer: (C)

Air brake endorsement is required only if the vehicle used for the road test has air brakes. The scenario that best fits this is a three-axle single-motor vehicle, because heavier, multi-axle trucks are almost always equipped with air braking systems. When you take the road test in such a vehicle, you’d need the Q endorsement to operate it legally. The other scenarios involve vehicles that may use hydraulic brakes or aren’t as reliably associated with air brakes for the test vehicle, so they aren’t the typical trigger for the endorsement.