CDL · General Knowledge · 6 min read
Responding to Crashes and Fires
- Identify the three essential steps to take at a crash scene to protect people and property.
- Recognize the common mechanical, electrical, and cargo causes of commercial vehicle fires and how to prevent them.
- Apply correct firefighting procedures and choose the proper extinguishing method based on fire classification.
Basic Steps and Protecting the Crash Scene
If you are involved in an accident and are not seriously hurt, your immediate responsibility is to act to prevent further damage or injury. The three basic steps you must take at any accident scene are to protect the area, notify authorities, and care for the injured. Above all else, the very first thing you must do at an accident scene is to prevent another accident from happening in that exact same location.
If your vehicle is the one involved in the crash, try to move it to the side of the road. Moving your vehicle to the roadside serves two vital safety purposes: it helps prevent another crash from occurring and it allows traffic to continue moving safely. If, on the other hand, you were not involved in the collision but choose to stop to help, make sure you park away from the accident. The area immediately surrounding the accident scene is needed for arriving emergency vehicles.
To properly protect the crash area from oncoming traffic, immediately turn on your vehicle flashers. Next, set out your reflective warning triangles to warn other drivers sharing the road. These reflective warning triangles must be placed so that approaching drivers can see them in time to avoid the crash scene completely. Taking these steps early creates a protective perimeter around everyone involved.
Common mistakes
- Avoid opening the hood during an engine fire if you can, and keep van or box trailer doors shut during a cargo fire; opening those doors supplies oxygen and can make the fire burn very fast.
- Using water on an electrical fire (risking severe electrical shock) or on a gasoline fire (which spreads the burning liquid and flames).
- Moving a severely injured person when there is no immediate threat from fire or oncoming traffic.
- Aiming a fire extinguisher up into the visible flames instead of staying back and aiming directly at the source or base of the fire.
Key points
- At an accident scene, protect the area first, notify authorities, and care for the injured.
- If your vehicle is involved, try to get it to the side of the road; if you stop to help, park away from the accident so emergency vehicles have room.
- Help prevent vehicle fires by inspecting the electrical, fuel, and exhaust systems, tires, and cargo, and checking that your fire extinguisher is charged.
- If a fire occurs while driving, pull off the road and stop in an open area away from anything that might catch fire; do not pull into a service station. For an engine fire, turn off the engine as soon as you can.
- For an engine fire, avoid opening the hood if you can and shoot foam through the louvers, radiator, or vehicle’s underside; for a cargo fire in a van or box trailer, keep the doors shut.
- Select the right extinguishing agent for the class of fire, position yourself upwind, aim at the base, and continue until the material is completely cooled.
Practice this section
Explained CDL General Knowledge questions, no account needed. CDL General Knowledge practice test
The full lesson continues with 4 more sections with exam tips, audio in English and Spanish, 5 Check yourself questions and 20 flashcards.
- 1 month
$44.99$22.49 - 3 months
$131.99$65.99 - Lifetime
$269.99$134.99
One payment, no subscription.
See CDL plansAlready a member? Log in
Sample lesson: Licensing and Medical Requirements25 practice questions on this exam
Each CDL practice test has 25 original questions with the answers explained. No account needed.
Open the CDL practice testsOriginal lesson written for CDL practice · updated October 29, 2026. Exam names are trademarks of their owners; tests.global is not affiliated with them.