Bad Weather & Night Driving — Louisiana
Louisiana CDL practice test: 410 free practice questions (Based on the official driver handbook). The official format is not yet verified; check the official site before your test. Bad Weather & Night Driving: 18 questions.
Rain, snow, ice, fog and night driving: visibility, traction and headlight use.
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 | Bad Weather & Night Driving |
| License test | Louisiana CDL permit (CLP) knowledge tests |
| Topic questions | 18 (4% of 410 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 (18)
1. The trailer hand valve should not be used while you are driving because:
- It will disconnect from the vehicle.
- You will stop the vehicle too quickly.
- It can cause a skid. ✓
Answer: C. It can cause a skid.
The trailer hand valve should not be used while driving because it can cause the trailer to skid. The handbook says the trailer hand valve, also called the trolley valve or Johnson bar, works the trailer brakes and should be used only to test them. It warns that using it while driving creates a danger of making the trailer skid. The foot brake sends air to all the brakes, including the trailer's, and the handbook says there is much less chance of a skid or jackknife when you use just the foot brake.
2. If there is ice on the front of your side mirror:
- You should exit the roadway.
- You can expect ice to be on the roadway. ✓
- There will not be ice on the roadway.
Answer: B. You can expect ice to be on the roadway.
If there is ice on the front of your side mirror, you can expect ice to be on the roadway. The handbook lists vehicle icing as a sign of slippery roads. It says to open the window and feel the front of the mirror, mirror support, or antenna; if ice is there, the road surface is probably starting to ice up. Another passage says that ice on mirrors or wiper blades means the road most likely will be icy as well. So ice on the front of your side mirror is a warning to expect ice on the road and to slow down.
3. Hydroplaning:
- Only occurs at extremely high speeds.
- Can occur at speeds as low as 30 mph. ✓
- Happens most frequently when tire pressure is too high.
Answer: B. Can occur at speeds as low as 30 mph.
Hydroplaning can occur at speeds as low as 30 mph when there is a lot of water on the road. The handbook says plainly that hydroplaning can happen at speeds as low as 30 mph if there is a lot of water. It also notes that it does not take much water to cause it. So the idea that you must be driving extremely fast to lose traction on wet pavement is wrong, and tire condition matters too: low pressure or worn tread makes hydroplaning more likely because the grooves cannot carry water away.
4. Hydroplaning happens most often when:
- A vehicle is traveling faster than 60 mph.
- Tire pressure is too low. ✓
- Tire tread is too deep.
Answer: B. Tire pressure is too low.
Hydroplaning happens most often when tire pressure is too low. The handbook says low tire pressure makes hydroplaning more likely, and worn tread does too. It explains that tire grooves carry water away, so grooves that are not deep enough do not clear the water well. The same passage also says hydroplaning can happen even at 30 mph when there is a lot of water, so the key setup is low pressure or worn tread, not simply a high speed.
5. When driving on packed snow, you should reduce your speed by:
- One-half or more. ✓
- About one-third.
- About one-quarter.
Answer: A. One-half or more.
When driving on packed snow, reduce your speed by one-half or more. The handbook pairs each road surface with a speed reduction. On a wet road, it says to cut speed by about one-third. For packed snow, it goes further and says to reduce speed by a half, or more. Slippery surfaces make stopping and turning harder, so you need to slow down to keep control. The packed snow guidance therefore matches the choice of one-half or more.
6. When driving in fog, you should:
- Slow down. ✓
- Speed up.
- Drive on the shoulder.
Answer: A. Slow down.
Slow down when driving in fog. The handbook warns that fog can appear without warning and visibility can drop fast. It says to be ready to reduce speed and to slow down before you enter fog. If fog is bad enough, it is better to pull off the road into a rest area or truck stop than to keep driving. That supports slowing down rather than trying to drive faster or treating the shoulder as a travel lane.
7. If a vehicle begins to hydroplane, the driver should:
- Accelerate.
- Release the accelerator and push in the clutch. ✓
- Pull in the clutch and brake.
Answer: B. Release the accelerator and push in the clutch.
8. On slippery roads, you should:
- Accelerate and slow down frequently.
- Adjust your driving to match weather conditions. ✓
- Tailgate other vehicles.
Answer: B. Adjust your driving to match weather conditions.
On slippery roads you should adjust your driving to match the weather conditions — slowing down and driving smoothly. The handbook says traction is the friction between your tires and the road, and slippery surfaces cut that traction so it takes longer to stop and is harder to turn without skidding. It tells you to drive slower on wet roads and much slower on snow or ice, to start gently, make turns gently, avoid hard braking, and allow a longer following distance. Matching your speed, turning, braking, and space to the conditions is exactly what adjusting your driving means.
9. Water that has collected on a roadway can cause:
- Hydroplaning. ✓
- Acceleration.
- Stopping.
Answer: A. Hydroplaning.
Water collected on a roadway can cause hydroplaning. When water or slush collects on the road, the handbook says your vehicle can hydroplane. The tires lose contact with the road and have little or no traction, so you might not be able to steer or brake. Another passage says surfaces where water collects create the conditions for hydroplaning. That matches the answer: the collected water causes hydroplaning.
10. A thin layer of ice that forms on road surfaces is called:
- White ice.
- Black ice. ✓
- Blue ice.
Answer: B. Black ice.
A thin layer of ice on a road surface is called black ice. The handbook's slippery-road section defines black ice as a thin, clear layer that lets you see the pavement underneath. Because it is clear, it can make the road look wet instead of icy. The passage also warns that when the temperature is below freezing and the road looks wet, you should watch for black ice. That description matches the question exactly, so black ice is the correct term.
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Last checked: 2026-10-17 · Verified from official source
Updated: · Based on the official driver handbook