Vehicle Hazards, Stabilization, and Access Practice Questions

25 multiple-choice questions on Vehicle hazards, stabilization, and access for paramedic and EMT students, from Chapter 49 (Vehicle Extrication and Special Rescue). Read each question, pick your answer, then tap Show answer to check it and read the explanation.

25 practice questions

1. Rescuers disconnect a crashed car's 12-volt battery. Undeployed airbags are still not safe right away because:

   1. A. A backup capacitor can still fire them
   2. B. The airbags run on a separate fuel cell
   3. C. Airbags use crash sensors, not current
   4. D. The cables reconnect when the car moves
   Show answer

   Answer: A. A backup capacitor can still fire them

   Airbag control units have a reserve capacitor that can fire the airbags for a time after power is cut, from seconds to minutes depending on the maker. Rescuers therefore still stay out of deployment paths; airbags do need electrical current to fire, so the sensor-only idea is a misconception.

2. Before cutting a car's roof pillars, rescuers peel away the interior trim mainly to:

   1. A. Expose fuel lines that run through the pillars
   2. B. Check for orange cables hidden in the pillars
   3. C. Find airbag inflators or belt pretensioners
   4. D. Lower the noise made by the hydraulic cutter
   Show answer

   Answer: C. Find airbag inflators or belt pretensioners

   Side curtain airbag inflators and seat belt pretensioners are often mounted in the pillars and roof rails, and cutting into one can make it fire or explode. Fuel lines and high-voltage cables run under the car, not up the pillars.

3. A seat belt pretensioner is a hazard during extrication because it can:

   1. A. Release toxic gas into the passenger area
   2. B. Fire suddenly and snap the belt tight
   3. C. Lock all doors when the battery is cut
   4. D. Leak fuel from a pressurized cylinder
   Show answer

   Answer: B. Fire suddenly and snap the belt tight

   Pretensioners use a small explosive or gas charge to tighten the belt in a crash; an undeployed one can fire if cut or heated, injuring the patient or a rescuer. They do not lock doors or contain fuel.

4. After a crash, a hybrid car's ignition is on and the dash shows 'Ready,' but the engine is silent. The car should be considered:

   1. A. Off, since the engine is silent
   2. B. Off once the doors are opened
   3. C. Safe once the headlights are off
   4. D. Running and able to move
   Show answer

   Answer: D. Running and able to move

   A hybrid or electric vehicle can be on and able to move silently, because the gas engine runs only when needed. Rescuers must put it in park, set the brake, and turn the ignition off; a quiet engine does not mean the car is off.

5. On hybrid and electric vehicles, high-voltage cables are identified by their:

   1. A. Bright yellow covering
   2. B. Thick black insulation
   3. C. Bright orange covering
   4. D. Red and black stripes
   Show answer

   Answer: C. Bright orange covering

   High-voltage cables are orange so that rescuers can recognize them and avoid cutting them. Yellow and blue are used on some lower-voltage circuits, and black or red cables are ordinary 12-volt wiring.

6. After turning off a crashed electric car with push-button start, rescuers should also:

   1. A. Leave the key fob on the dashboard
   2. B. Move the key fob well away from the car
   3. C. Cut the orange cables to the battery
   4. D. Pry open the high-voltage battery case to check it
   Show answer

   Answer: B. Move the key fob well away from the car

   With a smart key nearby, a push-button vehicle can be restarted by accident, so the fob is moved well away, often at least 5 m (16 ft). Cutting orange cables or opening the battery case exposes rescuers to lethal voltage.

7. An electric car's damaged battery pack is hissing and popping after a crash. Rescuers should anticipate:

   1. A. A fire that may reignite hours later
   2. B. A brief fire that is easily put out
   3. C. A static shock if the car is touched
   4. D. A small leak of harmless coolant fluid
   Show answer

   Answer: A. A fire that may reignite hours later

   Damaged lithium-ion cells can go into thermal runaway, producing toxic gas and an intense fire that needs large amounts of water and can reignite hours or days later. Treating it as a small, easily controlled fire puts rescuers and the patient at risk.

8. A sedan is upright on all four wheels after a crash. Standard stabilization includes:

   1. A. Chocking the wheels and cribbing under the frame
   2. B. Raising the car on a jack before anyone enters
   3. C. Chocking the front wheels alone
   4. D. Setting the parking brake with no cribbing under the car
   Show answer

   Answer: A. Chocking the wheels and cribbing under the frame

   Wheel chocks stop rolling, and cribbing or step chocks under the frame stop the car from bouncing on its suspension. Raising the car on a jack makes it less stable, and chocks or the parking brake without cribbing still let the car bounce on its suspension.

9. You are the first rescuer to enter an upright car after it has been chocked and cribbed. Before patient care, you should:

   1. A. Unbuckle the patient's belt to prepare removal
   2. B. Slide the seat back to make room to work
   3. C. Lower every window with the power switches
   4. D. Put it in park, set the brake, and turn it off
   Show answer

   Answer: D. Put it in park, set the brake, and turn it off

   Placing the car in park, setting the parking brake, and turning off the ignition prevent it from moving and reduce electrical and fuel hazards. Moving the seat or unbuckling the patient before assessment can worsen a spine injury.

10. A minivan is resting on its side after a rollover. It is best stabilized with:

    1. A. Rocking it back onto its wheels
    2. B. Struts and cribbing on both sides
    3. C. Wheel chocks under each of its tires
    4. D. A rope from the roof to the engine
    Show answer

    Answer: B. Struts and cribbing on both sides

    A vehicle on its side has a narrow base and can tip either way, so struts and cribbing are placed on both sides. Rocking it back onto its wheels could injure the occupants and is done only as a planned rescue step.

11. A car has come to rest on its roof. Stabilization should focus on:

    1. A. Rolling it back upright before patient access
    2. B. Chocking the tires that are now up in the air
    3. C. Cribbing at the hood and trunk to stop rocking
    4. D. Leaving it to rest on the roof without support
    Show answer

    Answer: C. Cribbing at the hood and trunk to stop rocking

    An overturned car rocks on its curved, crushed roof, so cribbing is placed between the ground and the hood and trunk areas. Rolling it upright before patients are out can cause further injury.

12. Box cribbing is built by:

    1. A. Stacking all pieces in one direction
    2. B. Stacking wood pieces in crossed pairs
    3. C. Wedging one large block under the frame
    4. D. Nailing boards together into a triangle
    Show answer

    Answer: B. Stacking wood pieces in crossed pairs

    Box cribbing alternates layers of two pieces at right angles, like a log cabin, which spreads the load and resists tipping. Stacking pieces in one direction makes a tower that can roll or slide.

13. The side and rear windows of most cars are tempered glass, which when broken:

    1. A. Shatters into small, blunt pieces
    2. B. Cracks but stays together in a sheet
    3. C. Breaks into long, sharp, jagged shards
    4. D. Must be cut out with a saw
    Show answer

    Answer: A. Shatters into small, blunt pieces

    Tempered glass is designed to break into many small, rounded pieces that are less likely to cut deeply. Staying together in a sheet describes laminated glass, which is used in windshields.

14. Rescuers need to remove a crashed car's windshield. Because it is laminated glass, it is usually removed by:

    1. A. Striking a corner with a center punch
    2. B. Pushing it in with a gloved hand
    3. C. Cutting it out with a glass saw
    4. D. Spraying it with water to crack it
    Show answer

    Answer: C. Cutting it out with a glass saw

    A laminated windshield has a plastic layer between two sheets of glass, so it does not shatter; it is cut out with a glass saw or axe. A center punch works on tempered glass, not on laminated glass.

15. When breaking a tempered side window with a spring-loaded center punch, the best place to strike is:

    1. A. The exact center of the window
    2. B. The top edge next to the roof
    3. C. The part closest to the patient
    4. D. A lower corner of the window
    Show answer

    Answer: D. A lower corner of the window

    Glass is most rigid near the frame, so a punch at a lower corner breaks it easily, and the glass falls downward. Striking near the patient sends glass toward the person you are protecting.

16. Simple access to a trapped patient is gained by:

    1. A. Spreading a door with hydraulic tools
    2. B. Opening doors or windows without tools
    3. C. Removing the roof with a power saw
    4. D. Cutting the B-post and folding the doors
    Show answer

    Answer: B. Opening doors or windows without tools

    Simple access uses no tools: opening a door, rolling down a window, or asking the patient to unlock it. Spreading doors and removing roofs are complex access, which needs tools and training.

17. A driver is trapped in a car with crushed front doors. Before rescuers start the hydraulic spreader, you should:

    1. A. Try every door and ask her to unlock one
    2. B. Break the windshield so you can talk to her
    3. C. Start an IV through the side window first
    4. D. Have her climb out across the center console
    Show answer

    Answer: A. Try every door and ask her to unlock one

    'Try before you pry': a rear door or the passenger door may open normally, giving fast simple access without tools. Breaking the windshield is slow and dangerous, and climbing over the console could worsen an injury.

18. In vehicle rescue terms, the B-post is the:

    1. A. Pillar on each side of the windshield
    2. B. Pillar just behind the rear passenger doors
    3. C. Pillar between the front and rear doors
    4. D. Floor support under the front seats
    Show answer

    Answer: C. Pillar between the front and rear doors

    Roof pillars are lettered from front to back: the A-posts frame the windshield, the B-posts sit between the front and rear doors, and the C-posts are behind the rear doors. Knowing the names lets rescuers and medics talk clearly about cuts.

19. Removing the roof during an extrication is most helpful because it:

    1. A. Stops the airbags from firing during cuts
    2. B. Removes the risk of a fuel tank fire
    3. C. Spares the need to stabilize the vehicle
    4. D. Gives wide access and a straight path out
    Show answer

    Answer: D. Gives wide access and a straight path out

    With the roof off, rescuers can reach the patient from above and slide him out along a long board in line with the spine. Roof removal does not disable airbags or remove the need for stabilization.

20. A driver's legs are pinned by a dashboard and steering column pushed into the footwell. The technique most likely to free them is:

    1. A. A door pop at the front hinge
    2. B. A rear window removal
    3. C. A side window break
    4. D. A dash roll or dash lift
    Show answer

    Answer: D. A dash roll or dash lift

    A dash roll or lift pushes the dashboard and column up and forward, off the patient's legs. Opening a door or window gives access but does not move what is pinning the legs.

21. Rescuers find that their cutter cannot cut through a late-model car's B-post. The most likely reason is:

    1. A. Cold weather has made the metal harder
    2. B. The post is made of high-strength steel
    3. C. The pillar holds a hidden high-voltage cable
    4. D. The post is reinforced with aluminum bars
    Show answer

    Answer: B. The post is made of high-strength steel

    Newer cars use ultra-high-strength and boron steel in pillars, which can stop older cutters, so rescuers need stronger tools or a different plan. High-voltage cables are not in the pillars. Cold does not harden steel enough to stop a cutter, and aluminum is softer than steel and cuts easily.

22. Fuel is leaking from a crashed car's tank onto the road. The best initial approach is to:

    1. A. Flush it into the storm drain with water
    2. B. Wait for the fire crew before doing anything
    3. C. Remove ignition sources and absorb the spill
    4. D. Turn off the car and let the fuel evaporate
    Show answer

    Answer: C. Remove ignition sources and absorb the spill

    Controlling ignition sources and containing the fuel with absorbent reduces the fire risk. Flushing fuel into a drain spreads the hazard. Letting it evaporate leaves vapor that can ignite, and simple measures such as removing ignition sources should not wait for the fire crew.

23. When disconnecting a crashed car's 12-volt battery, rescuers should first:

    1. A. Cut or remove the negative cable
    2. B. Cut or remove the positive cable
    3. C. Cut both cables together at once
    4. D. Pour water on the battery posts
    Show answer

    Answer: A. Cut or remove the negative cable

    Removing the negative (ground) cable first lowers the chance of a spark if a tool touches the car's metal frame. Cutting both cables together with one tool can short the battery and cause an arc.

24. Before the 12-volt battery of a crashed car is disconnected, rescuers may want to:

    1. A. Turn the headlights on to light the scene better
    2. B. Run the engine to keep the heater on for him
    3. C. Cycle the ignition off and on to reset the airbag system
    4. D. Use the power controls to open windows and move seats
    Show answer

    Answer: D. Use the power controls to open windows and move seats

    Once the battery is disconnected, power windows, seats, door locks, and tilt steering columns will not work, so rescuers use them first if they help access. Running the engine for heat adds fire and movement risk, and cycling the ignition does not disarm the airbags and can power the system. Headlights add battery drain and do not help access.

25. At an extrication, the paramedic notices that a rescuer has cut a door post and left the jagged end bare. Before anyone moves past it, the metal should be:

    1. A. Wiped clean of the patient's blood
    2. B. Covered with edge protection
    3. C. Bent outward toward the street
    4. D. Marked with a strip of tape
    Show answer

    Answer: B. Covered with edge protection

    Cut metal edges are sharp enough to cut through gloves and turnout gear, so rescuers cover them with edge protectors, tarps, or padding. Tape marks the hazard but does not protect anyone who brushes against it.