Bad Weather & Night Driving — Illinois
Illinois CDL practice test: 447 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 | Illinois CDL permit (CLP) knowledge tests |
| Topic questions | 25 (6% of 447 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 (25)
1. How much water is needed on a road surface for a vehicle to hydroplane?
- Usually several inches
- A good amount, such as a large puddle
- A small amount ✓
- No water
Answer: C. A small amount
2. 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.
3. The best way to recognize that your trailer has begun to skid is by:
- Seeing other drivers' faces.
- Seeing it in your mirrors. ✓
- Feeling it.
- Listening to the radio.
Answer: B. Seeing it in your mirrors.
The best way to catch a trailer skid early is by seeing it in your mirrors. The handbook's trailer skid procedure starts with recognizing the skid, and it says the earliest and best way to notice the trailer has started to skid is by watching it in your mirrors. It adds that whenever you brake hard, you should check the mirrors to confirm the trailer is staying where it belongs, because once the trailer swings out of your lane a jackknife becomes very hard to prevent. So the skill it teaches is a visual habit: hard braking means a mirror check.
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. How much water needs to be on the surface of a road 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
6. When should you watch out for black ice?
- When it is snowing
- When the temperature is below freezing and the road looks wet ✓
- When the temperature is above freezing and there is snow on the ground
- Just after a rainstorm
Answer: B. When the temperature is below freezing and the road looks wet
Watch for black ice whenever the temperature is below freezing and the road looks wet. The handbook describes black ice as a thin, clear layer that lets the pavement show through, so the surface can look wet rather than icy. It gives a simple rule: whenever the temperature is below freezing and the road appears wet, black ice is a hazard to watch for. That matches the condition in the correct choice: below-freezing temperatures plus a wet-looking road.
7. What is black ice?
- A thick layer of ice on the road
- A thin layer of ice on the road ✓
- Ice that is black from debris on the road
- Ice that is easily seen
Answer: B. A thin layer of ice on the road
Black ice is a thin layer of ice on the road that is clear enough to see the pavement underneath. The handbook describes black ice as a thin, clear coating that lets the pavement show through, so the road looks wet rather than icy. It also says to watch for black ice whenever the temperature is below freezing and the road looks wet. That matches a thin layer of ice on the road, not a thick slab or ice colored by debris.
8. When driving on packed snow, you should reduce your speed:
- By at least one-half. ✓
- By about one-third.
- By about one-quarter.
- By about one-eighth.
Answer: A. By at least one-half.
On packed snow, reduce your speed by at least one-half. The handbook ties speed to traction: on a slippery surface it takes longer to stop and is harder to turn without skidding. It gives a specific cut for packed snow: reduce speed by a half, or more. That matches the answer calling for at least one-half. The same passage gives a smaller reduction, about one-third, for a wet road, so it is the packed-snow figure that supports going slower by half or more.
9. If a trailer begins to skid, the driver should:
- Lock the brakes.
- Release the brakes. ✓
- Steer in the opposite direction.
- Accelerate.
Answer: B. Release the brakes.
Release the brakes so the trailer wheels can regain traction. The handbook says that when a trailer starts to skid, you should release the brakes to get traction back. It explains that the trailer wheel brakes caused the skid, so using the trailer hand brake to try to straighten the rig is the wrong move. Once the trailer wheels grip the road again, the trailer will follow the tractor and straighten out.
10. Which of the following is not an example of a driver who might be a hazard?
- A driver operating a vehicle without first scraping ice off the windshield
- The operator of a rental truck
- The driver of a station wagon with items covering the back windows
- A person operating a pick-up truck ✓
Answer: D. A person operating a pick-up truck
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Last checked: 2026-10-17 · Verified from official source
Updated: · Based on the official driver handbook