DOT Inspector Safety and Hazard Identification 3 — Questions and Answers
Question 1: When should an inspector use wheel chocks during a vehicle inspection?
- Only when inspecting vehicles on inclines greater than 10 degrees
- Whenever the vehicle is parked for inspection to prevent unintended movement (Correct answer)
- Only if the parking brake is found to be defective
- Wheel chocks are the driver's responsibility, not the inspector's
Correct answer: Whenever the vehicle is parked for inspection to prevent unintended movement
Wheel chocks should be placed whenever a vehicle is stationary for inspection to eliminate risk of rollaway regardless of parking brake condition.
Question 2: An inspector finds that a vehicle is carrying compressed gas cylinders that are not secured. What hazard does this primarily present?
- Increased vehicle weight exceeding axle limits
- Projectile hazard if cylinders fall and valve stems break (Correct answer)
- Regulatory paperwork violation only
- Risk of slow gas leak causing long-term exposure
Correct answer: Projectile hazard if cylinders fall and valve stems break
Unsecured compressed gas cylinders can become high-velocity projectiles if they fall and the valve stem is sheared off, presenting a lethal hazard.
Question 3: What is the minimum safe distance an inspector should maintain from a placarded hazmat vehicle while awaiting hazard identification?
- 10 feet
- 25 feet
- At least 100 feet upwind and uphill (Correct answer)
- 50 feet downwind
Correct answer: At least 100 feet upwind and uphill
The Emergency Response Guidebook recommends at least 100 feet as an initial isolation distance, and inspectors should position themselves upwind and uphill from potential hazmat releases.
Question 4: A driver presents a shipping paper describing a flammable liquid shipment. The vehicle has no placard displayed. What action should the inspector take?
- Accept the driver's verbal assurance and continue inspection
- Place the vehicle out of service for improper placarding (Correct answer)
- Issue a warning and allow the driver to attach placards on site
- Verify with the shipper before making any determination
Correct answer: Place the vehicle out of service for improper placarding
Failure to display required placards for a hazmat shipment is a violation that requires placing the vehicle out of service per 49 CFR 177.823.
Question 5: Why must inspectors avoid standing directly behind a vehicle during a brake check with the engine running?
- Exhaust fumes are more concentrated at the rear
- Sudden brake release can cause the vehicle to roll backward rapidly (Correct answer)
- Rear lighting checks require a different position
- Anti-lock braking system sensors can be damaged by proximity
Correct answer: Sudden brake release can cause the vehicle to roll backward rapidly
If a vehicle rolls or lurches backward during a brake application test, an inspector standing directly behind it has no time to escape being struck.
Question 6: Which type of hazard does a cracked or delaminated tire present beyond a blowout risk?
- Increased rolling resistance only
- Potential for tire tread separation causing debris strikes to nearby vehicles and inspectors (Correct answer)
- Reduced fuel efficiency
- Electrical grounding issues on the vehicle
Correct answer: Potential for tire tread separation causing debris strikes to nearby vehicles and inspectors
Delaminating tires can shed tread at highway speeds, creating high-velocity debris capable of injuring inspectors or causing accidents to nearby traffic.
Question 7: When performing a visual inspection of a vehicle's undercarriage, what is the safest body position?
- Lying flat under the vehicle for an unobstructed view
- Using a mirror and flashlight from outside the vehicle's footprint (Correct answer)
- Crouching directly under the frame near the front axle
- Entering from the rear axle only when air brakes are applied
Correct answer: Using a mirror and flashlight from outside the vehicle's footprint
Using an inspection mirror and flashlight from outside the vehicle's footprint eliminates the risk of being crushed if the vehicle moves or collapses.
DOT Inspector Safety and Hazard Identification 3
When should an inspector use wheel chocks during a vehicle inspection?