Which of these vehicles are excepted?
Scenario 1: A truck tractor with three axles that was manufactured on January 15, 1978, and only has brakes on the rear wheels. Is this vehicle excepted from requiring brakes acting on all wheels?
Yes
No
Scenario 2: A full trailer with a gross weight rating of 3,000 pounds whose axle weights are around 1,500 pounds each. The towing vehicle has a gross weight of 3,400 pounds when the axle weights are totaled. Is this vehicle excepted from requiring brakes acting on all wheels?
Yes
No
Scenario 3: A three-axle dolly with a steering axle that does not require a co-driver to steer it. Is this vehicle excepted from requiring brakes acting on all wheels?
Yes
No
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Which of these vehicles are excepted?: Answers
Scenario 1 Answer: Yes. Trucks or truck tractors having three or more axles and manufactured before July 25, 1980, are not required to have brakes on the front wheels. These vehicles must meet the brake performance requirements in 393.52. Because this vehicle was manufactured in 1978, it is excepted from requiring brakes on all wheels.
Scenario 2 Answer: No. Any full trailer or four-wheel pole trailer (laden or unladen) with a gross weight of 3,000 pounds or less is not required to be equipped with brakes if the sum of the axle weights of the towed vehicle does not exceed 40 percent of the sum of the axle weights of the towing vehicle. Since the sum of this vehicle’s axle weights are well over 40 percent of the sum weight of the towing vehicle (sum of trailer axle weights is 3,000 pounds, the power unit is 3,400 pounds), this vehicle is not excepted.
Scenario 3 Answer: No. Brakes are not required on the steering axle of a three-axle dolly which is steered by a co-driver, but since this vehicle is being steered without a co-driver, the vehicle is not excepted from the brake rules.