Speed Limits & Following Distance — Washington
Washington CDL practice test: 386 free practice questions (Based on the official driver handbook). The official format is not yet verified; check the official site before your test. Speed Limits & Following Distance: 10 questions.
Posted speed limits, school and construction zones, stopping and following distance.
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 | Speed Limits & Following Distance |
| License test | Washington CDL permit (CLP) knowledge tests |
| Topic questions | 10 (3% of 386 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 (10)
1. The "crack-the-whip" effect is caused by:
- Rearward amplification. ✓
- Driving below the speed limit.
- Heavy traffic.
Answer: A. Rearward amplification.
The crack-the-whip effect is caused by rearward amplification. The handbook says rearward amplification produces the crack-the-whip effect. In a quick lane change, the rear trailer can swing and tip more easily than the tractor. The chart compares combination vehicles, and triples have a rearward amplification of 3.5, meaning the last trailer can roll over much more easily than a five-axle tractor. That is why the handbook tells you to steer gently and smoothly with trailers, because a sudden steering movement can tip a trailer over.
2. An Individual Vehicle Distance Record (IVDR) does not need to include which of the following?
- The dates of a trip
- The total distance traveled
- The number of vehicles passed ✓
Answer: C. The number of vehicles passed
An Individual Vehicle Distance Record does not need to include the number of vehicles passed. The handbook describes the IVDR as a trip record that shows the distance traveled and the fuel purchased for a vehicle running interstate under apportioned registration and IFTA credentials. It also says that although the layout of the form can differ, the information required for proper record keeping stays the same, and the licensee must keep records that back up the quarterly tax return. Counting the vehicles you pass has nothing to do with miles driven or fuel burned, so it falls outside what the record is meant to capture.
3. A ramp's posted speed limit:
- Is suitable for all vehicles.
- Is suitable for some vehicles, but may be too fast for a large CMV. ✓
- Is just a suggestion and may be exceeded.
Answer: B. Is suitable for some vehicles, but may be too fast for a large CMV.
A ramp's posted speed limit is suitable for some vehicles, but it may be too fast for a large CMV. The handbook says off ramps and on ramps often have posted speed limit signs, and it warns that those speeds may be safe for automobiles but may not be safe for larger or heavily loaded vehicles. That is why the sign is not a guarantee for your truck. A downhill exit that also turns is especially risky because the downgrade makes it hard to slow down, and braking while turning is dangerous. The safe approach is to be going slowly enough before you reach the curved part of the ramp.
4. If you are being tailgated while driving a large vehicle, do all of the following, except:
- Reduce your speed gradually.
- Increase your following distance.
- Increase your speed. ✓
Answer: C. Increase your speed.
Increase your speed is the one thing you should not do when a vehicle is tailgating you. The handbook's advice for a tailgater starts with avoiding quick changes: signal early and bring your speed down gradually rather than suddenly. It also says to open up the room in front of you, because that extra space means you won't have to make abrupt speed or direction changes and it gives the tailgater an easier chance to pass. On speeding up, the handbook is direct: don't. Being followed closely is safer at a low speed than at a high speed. So the item that does not belong on the list is increasing your speed.
5. If another driver is tailgating you, you should:
- Move into the left lane.
- Speed up.
- Increase the distance between you and the vehicle ahead. ✓
Answer: C. Increase the distance between you and the vehicle ahead.
When someone is tailgating you, increase the distance between your vehicle and the vehicle ahead of you. The handbook lists increasing your following distance as one of the things to do when you are being tailgated. Opening up room in front of you means you won't have to make sudden speed or direction changes, and it also gives the tailgater an easier chance to get around you. The same section warns against speeding up, since being tailgated at a low speed is safer than at a high speed, and it says to avoid tricks like flashing brake lights or turning on taillights.
6. If you are driving at a reduced speed in a construction zone when you spot a construction worker near the road, you should:
- Speed up.
- Stay at your current speed.
- Further reduce your speed. ✓
Answer: C. Further reduce your speed.
You should further reduce your speed when a construction worker is near the road. The handbook says speeding traffic is the leading cause of injury and death in roadway work zones. It tells you to observe posted limits, watch your speedometer so it does not creep up through long construction sections, and slow for bad weather or road conditions. It then says to decrease your speed even further when a worker is close to the roadway. Since you are already driving at a reduced speed in a construction zone, seeing a worker near the road calls for one more reduction, not holding steady or speeding up.
7. What is a bobtail tractor?
- A tractor without a semi-trailer ✓
- A tractor with two semi-trailers
- A tractor that travels faster than the speed limit
Answer: A. A tractor without a semi-trailer
A bobtail tractor is a tractor without a semi-trailer. The handbook uses the term bobtail for a tractor that is running without a semi-trailer attached. It also warns that these tractors can be hard to stop smoothly and may take longer to stop than a fully loaded tractor-semitrailer. That description matches a tractor with no trailer, not a tractor pulling one or two trailers.
8. If you are braking on dry pavement while traveling at 55 mph, how much distance will brake lag add to your overall stopping distance?
- 32 feet ✓
- 45 feet
- 20 feet
Answer: A. 32 feet
Brake lag adds 32 feet to your overall stopping distance. The handbook explains that with air brakes there is a delay while air flows through the lines before the brakes actually work. At 55 mph on dry pavement, that brake lag distance is about 32 feet. The handbook also lists brake lag as one of the four parts of total stopping distance, along with perception, reaction, and braking distance. So the added distance from brake lag is 32 feet.
9. You should maintain at least ____ of following distance per every 10 feet of your vehicle when you are traveling more slowly than 40 mph.
- One second ✓
- Two seconds
- Three seconds
Answer: A. One second
You should keep at least one second of following distance for every 10 feet of your vehicle when traveling below 40 mph. The handbook gives a simple space-ahead rule: below 40 mph, allow at least one second for each 10 feet of vehicle length. It illustrates this with a 40-foot vehicle needing 4 seconds and a 60-foot vehicle needing 6 seconds. When speed goes above 40 mph, the handbook says to add one more second. The bank answer matches that rule for speeds under 40 mph.
10. On a slippery surface, stopping distance:
- Is longer than on a regular driving surface. ✓
- Is not as long as on a regular driving surface.
- Is about the same as on a regular driving surface.
Answer: A. Is longer than on a regular driving surface.
On a slippery surface, stopping distance is longer than on a regular driving surface. The handbook says traction is the friction between tires and the road, and slippery conditions reduce it. It states directly that it will take longer to stop when the road is slippery, and wet roads can double stopping distance. That is why you must slow down to stop within the same distance you would need on a dry road. The correct choice simply matches that rule: a slippery surface makes the stop take more distance, not less.
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Last checked: 2026-10-17 · Verified from official source
Updated: · Based on the official driver handbook