Bad Weather & Night Driving — California
California CDL practice test: 392 free practice questions (20 official sample questions · Official driver handbook). The official format is not yet verified; check the official site before your test. Bad Weather & Night Driving: 21 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 | California CDL permit (CLP) knowledge tests |
| Topic questions | 21 (5% of 392 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
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Questions (21)
1. What should you do when you are driving at night?
- Make sure you are driving slow enough so you can stop within the range of your headlights in an emergency. ✓
- Roll down your window so that the fresh air will help keep you awake.
- If you are sleepy, drink coffee or other caffeine products.
Answer: A. Make sure you are driving slow enough so you can stop within the range of your headlights in an emergency.
2. When a heavy fog occurs you should:
- use high beams for best visibility.
- park off to the right side of the road with you parking lights on.
- park at a rest area or truck stop until the fog has lifted. ✓
Answer: C. park at a rest area or truck stop until the fog has lifted.
Park at a rest area or truck stop until the fog has lifted. The handbook's fog section gives blunt advice: the best thing to do about driving in fog is not to drive in it. It says you should preferably pull off the road into a rest area or truck stop and wait until visibility improves. That matches the choice of stopping somewhere off the roadway until the fog clears. If you truly have to keep going, the handbook adds that you should slow down before entering the fog, obey fog warning signs, and run low-beam headlights and fog lights, even during the day.
3. Roads are especially slippery when it first begins to rain because:
- Water is always very slippery.
- The fresh rain mixes with oil on the roadway. ✓
- The water has nowhere to go.
Answer: B. The fresh rain mixes with oil on the roadway.
The correct answer is that the fresh rain mixes with oil on the roadway. The handbook says that right after rain starts, the water mixes with oil left on the road by vehicles, and this makes the road very slippery. It also says that if the rain continues, it will wash the oil away. So the first rain is the risky time because the oil is still there and gets mixed with the water, not because water by itself is always slippery or because it has nowhere to go. That is why the answer points to fresh rain mixing with roadway oil.
4. What happens when a vehicle hydroplanes?
- The tires lose contact with the road. ✓
- The trailer disengages from the tractor.
- The vehicle becomes easier to control.
Answer: A. The tires lose contact with the road.
The tires lose contact with the road. The handbook compares hydroplaning to water skiing: water or slush builds up and the tires stop touching the pavement. With little or no traction, you may not be able to steer or brake. That matches the choice saying the tires lose contact with the road. The handbook also warns not to use the brakes to slow down while hydroplaning, and says low tire pressure or worn tread makes hydroplaning more likely.
5. 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.
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. Black ice is:
- Usually thick.
- Usually thin. ✓
- Not a hazard when driving.
Answer: B. Usually thin.
Black ice is usually thin — it is a thin, clear layer that lets you see the road underneath it. The handbook describes black ice as a thin layer that is clear enough to see the road underneath, which is why the road just looks wet. It also warns that any time the temperature is below freezing and the road looks wet, you should watch for black ice. So the layer itself is thin, not thick, and it is a real slipping hazard on cold, wet-looking pavement.
8. You are especially likely to encounter strong winds when:
- Coming out of tunnels. ✓
- Going into tunnels.
- Driving on shoulders.
Answer: A. Coming out of tunnels.
You are especially likely to meet strong winds when coming out of tunnels. The handbook's strong-wind section says strong winds make it hard to stay in your lane, and that this problem can be especially bad as you come out of a tunnel. That directly supports the answer. The passage does not tie the hazard to entering a tunnel or to driving on shoulders; it points to the moment you leave the sheltered tunnel and meet the wind.
9. When carrying Division 1.1, 1.2, or 1.3 explosives, your vehicle should not be:
- Parked within 300 feet of a bridge. ✓
- Parked within 40 feet of the road.
- Driven in rain or snow.
Answer: A. Parked within 300 feet of a bridge.
You should not park within 300 feet of a bridge when carrying Division 1.1, 1.2, or 1.3 explosives. The handbook's parking rule for these explosives forbids parking within 300 feet of a bridge, tunnel, building, place where people gather, or open fire, except for short operational stops such as fueling. It also says never park within five feet of the traveled part of the road. That makes the bridge-distance choice the one that matches the rule. The passages do not set a 40-foot road distance and do not ban driving in rain or snow.
10. Driving at night is:
- Safer than driving during the day.
- Just as safe as driving during the day.
- More dangerous than driving during the day. ✓
Answer: C. More dangerous than driving during the day.
Driving at night is more dangerous than driving during the day. The handbook opens its night-driving section by saying you are at greater risk after dark. In daylight you can spot hazards sooner; at night you cannot see them as quickly, so you have less time to react. A driver caught by surprise is less able to avoid a crash. The handbook also ties night driving to glare and fatigue, which impair vision and judgment. That combination supports the answer that night driving is more dangerous than daytime driving.
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Last checked: 2026-10-17 · Not yet verified
Updated: · 20 official sample questions · Official driver handbook