Bad Weather & Night Driving — District of Columbia
District of Columbia CDL practice test: 423 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: 25 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 | District of Columbia CDL permit (CLP) knowledge tests |
| Topic questions | 25 (6% of 423 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 (25)
1. Roads are slippery when it first begins to rain because:
- Water is slippery.
- The fresh rain mixes with oil on the roadway. ✓
- The water has nowhere to go.
- Concrete can be slippery.
Answer: B. The fresh rain mixes with oil on the roadway.
Roads are slippery when it first begins to rain because the fresh rain mixes with oil left on the roadway by vehicles. The handbook says that right after rain starts, the water mixes with oil that vehicles have left on the road, and that combination makes the pavement very slippery. It also notes that if the rain continues, it washes the oil away. So the first rain is the risky period, not simply because water or concrete is slippery in general. That is why the answer points to fresh rain mixing with oil.
2. How much water must be on a road surface for a vehicle to hydroplane?
- Usually several inches
- A good amount, such as a large puddle
- A small amount ✓
- None
Answer: C. A small amount
3. Rollovers are most likely to happen when:
- Drivers turn too fast. ✓
- Driver turn too slowly.
- It is windy.
- It is raining.
Answer: A. Drivers turn too fast.
Rollovers are most likely to happen when drivers turn too fast. The combination vehicles section states plainly that rollovers happen when you turn too fast, and it tells you to drive slowly around corners, ramps, and off ramps. It also explains that a higher center of gravity makes a truck easier to turn over, which is why cargo should sit as low as possible. Turning too fast is the behavior the handbook names as the cause, so slowing down in turns is the prevention it teaches.
4. Why are roads especially slippery right after it begins to rain?
- The water mixes with oil and grease on the road. ✓
- Roads are naturally slippery.
- Gravel often gets washed to the middle of the lane.
- Tires are not usually designed to drive in rain.
Answer: A. The water mixes with oil and grease on the road.
The road is especially slippery right after rain begins because water mixes with oil and grease left on the road by vehicles. The handbook's slippery-surfaces section lists the time just after rain begins as its own hazard. It says the water mixes with oil left by vehicles, making the road very slippery, and that continuing rain washes the oil away. That explains why the first part of a rain is the slick part. The same section says wet roads can double stopping distance and that you must slow down to stop in the same distance as on a dry road.
5. If you see lights ahead while driving in fog:
- You can assume the lights are on the road.
- It may be a reflection.
- It may be an optical illusion.
- The lights may not indicate where the road is as the vehicle may have pulled off the roadway. ✓
Answer: D. The lights may not indicate where the road is as the vehicle may have pulled off the roadway.
The lights ahead may not show where the road goes, because the vehicle they belong to may have pulled off the roadway. The fog section tells you to watch for vehicles on the side of the roadway. It warns that taillights or headlights you see ahead are not a reliable sign of where the road runs, since the vehicle may not be on the road at all. Instead of steering toward those lights, the handbook says to use roadside highway reflectors as your guide for how the road curves ahead. That makes the lights unreliable as a path marker.
6. Roads are most slippery right after it begins to rain because:
- The water mixes with oil and grease on the road. ✓
- The roads are naturally slippery.
- The gravel gets washed to the middle of the lane.
- Some tires are not designed for rain.
Answer: A. The water mixes with oil and grease on the road.
Roads are most slippery right after rain starts because the water mixes with oil left on the road by vehicles. The handbook lists "just after rain begins" as one of the signs of a slippery road. It explains that when rain first starts, the water combines with oil that vehicles have left on the surface, and this makes the road very slippery. It adds that if the rain keeps falling, it washes that oil away, so the worst grip comes early in the storm, not later. That is why you slow down and leave yourself room to stop on a wet road.
7. A person should not smoke within ____ of a vehicle placarded for Class 3 or Division 2.1 materials.
- 10 feet
- 25 feet ✓
- 100 feet
- 1,000 feet
Answer: B. 25 feet
You should stay at least 25 feet away from a placarded vehicle carrying Class 3 flammable liquids or Division 2.1 gases when you smoke. The no-smoking rule in the handbook sets one distance for these loads: keep smoking 25 feet away from a placarded cargo tank holding Class 3 flammable liquids or Division 2.1 gases. The same 25-foot limit applies to smoking or carrying a lighted cigarette, cigar, or pipe near any vehicle carrying those materials. So the bank answer matches the handbook exactly. The reason is straightforward: these are flammable liquids and gases, and a flame near them is a fire hazard, which is why the handbook names a fixed distance rather than leaving it to judgment.
8. Regarding winter driving, all of the following are true, except:
- Front tires should have a tread depth of at least 4/32 an inch.
- Tires should be slightly deflated. ✓
- Rear tires should have a tread depth of at least 2/32 an inch.
- Use a gauge to verify that each tire has a safe tread depth.
Answer: B. Tires should be slightly deflated.
The statement that is not true is that tires should be slightly deflated; the winter check is about having enough tread, not lowering tire pressure. The handbook's winter vehicle check says to make sure your tires have enough tread for traction. It gives minimum tread depths: at least 4/32 inch in every major groove on front tires and at least 2/32 inch on the other tires, with more being better. It also says to use a gauge to determine whether the tread is enough. The passage never says to deflate tires slightly, so that statement is the exception.
9. During the skills test, if making a turn that requires a stop, you should:
- Skid to a stop.
- Stop after the stop line to get a better view.
- Allow your vehicle to roll.
- Keep the front wheels aimed straight ahead. ✓
Answer: D. Keep the front wheels aimed straight ahead.
When a turn requires you to stop, keep the front wheels aimed straight ahead while you are stopped. The on-road driving section of the handbook lists this as one of the things you must do during the skills test: do not let the vehicle roll, and keep the front wheels aimed straight ahead. It appears next to the rule about leaving a safe gap when you stop behind another vehicle. Keeping the wheels straight is also what the handbook's steering guidance points toward, since it wants your steering inputs small and the vehicle held in a straight line rather than drifting or turning while you sit still.
10. Black ice is:
- Usually thick – about half an inch or more of ice.
- Usually thin. ✓
- Not a hazard when driving.
- Not really ice.
Answer: B. Usually thin.
Black ice is usually thin — a clear layer thin enough that the road shows through it. The handbook describes black ice as a thin layer that is clear enough to see the road underneath it, which makes the road look wet. Because it is clear rather than white or thick, you may not spot it as ice at all. The handbook adds that whenever the temperature is below freezing and the road looks wet, you should watch for black ice.
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Last checked: 2026-10-17 · Verified from official source
Updated: · Based on the official driver handbook