Speed Limits & Following Distance — Mississippi
Mississippi CDL practice test: 463 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: 15 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 | Mississippi CDL permit (CLP) knowledge tests |
| Topic questions | 15 (3% of 463 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 (15)
1. Because of tanks' high centers of gravity, drivers of tanks should:
- Take curves at the posted speed limit.
- Reduce their speed on curves. ✓
- Drive on the shoulder whenever possible.
- Slam on their brakes.
Answer: B. Reduce their speed on curves.
Drivers of tank vehicles should reduce their speed on curves. The handbook explains that a tank vehicle's high center of gravity makes it top-heavy and easy to roll over. It warns that tankers can turn over at the speed posted for a curve. So the safe approach is to slow down before the curve and travel well below the posted speed, then accelerate slightly through it.
2. When traveling more slowly than 40 mph, maintain at least ____ of following distance per every 10 feet of your vehicle.
- One second ✓
- Two seconds
- Three seconds
- Four seconds
Answer: A. One second
3. 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.
4. If being tailgated while driving a large vehicle, you should do all of the following, except:
- Reduce your speed gradually.
- Increase your following distance.
- Speed up. ✓
- Try to let the other vehicle pass.
Answer: C. Speed up.
You should not speed up when a large vehicle is being tailgated; the exception is to speed up. The handbook says that if you are being tailgated, avoid quick changes, signal early, and slow down gradually. It also says to increase your following distance, because more room ahead lets you avoid sudden speed or direction changes and makes it easier for the tailgater to get around you. It specifically says not to speed up, since being tailgated at a low speed is safer than at a high speed. Speeding up is the action that does not belong.
5. A posted speed limit for cars:
- Is usually safe for buses.
- May be too fast for buses. ✓
- May be too slow for buses.
Answer: B. May be too fast for buses.
A posted speed limit for cars may be too fast for buses. The handbook's passenger section warns that a curve's posted speed is set with cars in mind. In good weather that number can still be too high for many buses. A bus that takes the curve too fast may roll over if traction is good, or slide off if traction is poor. That is why the car speed limit is not automatically safe for a bus.
6. 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.
7. Stopping distance can be affected by:
- Speed. ✓
- Temperature.
- Time of day.
- Traffic.
Answer: A. Speed.
Stopping distance can be affected by speed; as speed increases, the distance needed to stop increases. The handbook's stopping-distance figure shows that braking distance grows sharply with speed: doubling speed makes braking distance four times longer, and tripling it makes it nine times longer. It also says high speeds increase stopping distances, while slowing down reduces braking distance. The total stopping-distance formula is perception distance plus reaction distance plus braking distance, and the air-brake section adds brake lag for those systems. Temperature and time of day do not appear as parts of that formula or as factors in the speed discussion.
8. Stopping distance can be affected by:
- Driving speed. ✓
- Temperature.
- Time of day.
Answer: A. Driving speed.
Driving speed affects stopping distance: as speed rises, the braking distance becomes much longer. The handbook's stopping-distance figure ties speed directly to braking distance. Going from 20 to 40 mph makes braking distance four times longer; going from 20 to 60 mph makes it nine times longer. It also says high speeds greatly increase stopping distances and that slowing down can reduce braking distance. The passage lists conditions such as traction, curves, visibility, traffic, and hills for speed adjustment, but it does not name temperature or time of day as stopping-distance factors.
9. If braking at a speed of 55 mph while driving on dry pavement, the brake lag can add ____ to your vehicle's total stopping distance.
- 32 feet ✓
- 15 feet
- 50 feet
- 10 feet
Answer: A. 32 feet
Brake lag at 55 mph on dry pavement adds about 32 feet to your total stopping distance. The handbook explains that with air brakes there is a delay called brake lag, the time it takes for air to move through the lines and reach the brakes after you push the pedal. Because of that delay, the vehicle keeps rolling a little before the brakes actually work. The handbook puts that added lag distance at roughly 32 feet when you are going 55 mph on dry pavement, and it lists brake lag distance as one of the four pieces of total stopping distance.
10. 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.
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Last checked: 2026-10-17 · Not yet verified
Updated: · Based on the official driver handbook