Vehicle Equipment & Safe Operation — Oregon
Oregon CDL practice test: 463 free practice questions (Based on the official driver handbook). The official format is not yet verified; check the official site before your test. Vehicle Equipment & Safe Operation: 190 questions.
Brakes, tires, lights, mirrors, seat belts, child seats and basic vehicle control.
This topic page is still being reviewed against the official handbook. Until review is finished it is hidden from search engines.
| Topic / Metric | Value |
|---|---|
| Topic | Vehicle Equipment & Safe Operation |
| License test | Oregon CDL permit (CLP) knowledge tests |
| Topic questions | 190 (41% of 463 total) |
| Review status | This topic page is still being reviewed against the official handbook. Until review is finished it is hidden from search engines. |
Official handbook
Not yet verified
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Questions (190)
1. When the wheels of a trailer lock up:
- The trailer will stay straight.
- The trailer tends to swing around. ✓
- The cab will swing, but the trailer will stay straight.
- They will likely go flat.
Answer: B. The trailer tends to swing around.
When the wheels of a trailer lock up, the trailer tends to swing around. The handbook states plainly that if a trailer's wheels lock up, the trailer tends to swing around, and that this is more likely when the trailer is empty or lightly loaded. It calls this a trailer jackknife. That is why the correct choice is the one saying the trailer tends to swing around. The passage ties the swing directly to trailer wheel lockup, so you should think of a locked trailer axle as a setup for the trailer to come around rather than track straight behind the tractor.
2. When adjusting your mirrors before a trip:
- No part of your vehicle should be visible in any mirror.
- Part of your vehicle should be visible in the mirrors. ✓
- More than half of each mirror should show the vehicle.
Answer: B. Part of your vehicle should be visible in the mirrors.
Adjust each mirror so that part of your vehicle is visible in it. The handbook says to check mirror adjustment before any trip, and it notes that this can only be done accurately when the trailer or trailers are straight. For each mirror, you should adjust it until some part of the vehicle shows. That visible piece acts as a reference point, helping you judge where the other images in the mirror sit. The rule is not to clear the mirror completely or to fill most of it with your own vehicle; a portion of the vehicle should remain in view.
3. If there is a cargo fire in a box trailer:
- The trailer doors should be opened.
- The trailer doors should not be opened. ✓
- A large, heavy blanket should be put over the trailer.
Answer: B. The trailer doors should not be opened.
Keep the trailer doors shut and do not open them when there is a cargo fire in a box trailer. The handbook says that for a cargo fire in a van or box trailer, you should keep the doors shut, especially if the cargo contains hazardous materials. It explains that opening the doors supplies the fire with oxygen and can make it burn very fast. Another section adds that if trailer doors feel hot, you may have a cargo fire and should not open them, since opening the doors lets air in and may make the fire flare up.
4. When a tire goes flat, you may hear a loud bang. The truck will be affected:
- Immediately.
- After a short delay. ✓
- Only if the damaged tire is near the front of the truck.
- Only if the truck is hauling a load.
Answer: B. After a short delay.
The truck will be affected after a short delay — it can take a few seconds before the vehicle reacts to a blowout. The handbook lists sound as a major sign of tire failure, and the loud bang of a blowout is easy to recognize. It also says it can take a few seconds for your vehicle to react, which is why you might briefly think the bang came from some other vehicle. So the noise comes first and the change in how the truck handles comes slightly later. The handbook's advice follows from that gap: any time you hear a tire blow, assume it is yours and be ready to respond.
5. When applying your brakes, the vehicle should:
- Pull to one side.
- Squeak.
- Not pull to either side. ✓
Answer: C. Not pull to either side.
When you apply the brakes, the vehicle should not pull to either side. The inspection passage says to drive forward at 5 mph, apply the service brake, and stop. After stopping, you check that the vehicle does not pull to either side and that it stops when the brake is applied. The passage adds that if the vehicle pulls to one side or does not stop well, the brakes may not be working correctly. So a straight, even stop is the sign of brakes working right.
6. Older trailers are not equipped with spring brakes. This means that if the air supply for a vehicle's air braking system leaks away:
- The trailer will stop normally.
- The trailer will not have brakes. ✓
- The trailer will speed up.
Answer: B. The trailer will not have brakes.
If the air supply leaks away on an older trailer without spring brakes, the trailer will have no brakes. The handbook says older trailers may not have spring brakes. Without them, a trailer that loses air from its tank has no emergency brakes, and its wheels can turn freely. The handbook also explains that trailers without spring brakes may have emergency brakes that work from stored air, but those brakes hold only while pressure remains; once the air leaks away, no brakes are left. That is why losing the air supply leaves the trailer with no brakes instead of stopping it normally.
7. An Anti-Lock Braking System (ABS) will:
- Allow you to drive faster than you would be able to otherwise.
- Allow you to follow other vehicles more closely than you would be able to otherwise.
- Allow you to drive less carefully than you would be able to otherwise.
- Not decrease your stopping distance. ✓
Answer: D. Not decrease your stopping distance.
An Anti-Lock Braking System will not decrease your stopping distance; it may help you keep control during hard braking, but it does not necessarily shorten the stop. The handbook says ABS does not necessarily shorten your stopping distance, though it helps you keep the vehicle under control during hard braking. It works as an add-on to your normal brakes, not a replacement, and it does not increase or decrease ultimate stopping power. That is why the correct choice is the one saying ABS will not decrease your stopping distance. The handbook also rejects the ideas that ABS lets you go faster, follow more closely, or be less careful.
8. When using your turn signal, you should:
- Signal before beginning the turn. ✓
- Turn the signal off before beginning the turn.
- Signal only if vehicles are in front of you.
Answer: A. Signal before beginning the turn.
9. Most heavy vehicles use the ____ method when changing gears.
- Double clutching ✓
- Double shifting
- Triple clutching
Answer: A. Double clutching
Most heavy vehicles use double clutching when changing gears. The handbook says heavy vehicles with unsynchronized manual transmissions require double clutching to change gears. It also notes that synchronized manual transmissions do not need it. Getting into the right gear matters because poor gear selection reduces control, and the basic manual method involves releasing the accelerator, pushing in the clutch, and shifting to neutral while the engine and gears slow to the rpm needed for the next gear. That supports the bank answer.
10. A ____ allows a driver to gradually apply spring brakes.
- Modulating control valve ✓
- Trailer air supply control
- Relay valve
Answer: A. Modulating control valve
A modulating control valve lets a driver apply the spring brakes gradually. The handbook describes a control handle on the dash of some vehicles that applies the spring brakes slowly instead of all at once, and calls it a modulating valve. It is spring-loaded, so you feel the braking as you move the lever, and the farther you move it the harder the spring brakes come on. The passage says the purpose is to let you control the spring brakes if the service brakes fail, so you can stop smoothly rather than slam them on.
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Last checked: 2026-10-17 · Verified from official source
Updated: · Based on the official driver handbook