Michigan CDL practice test: 371 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. Updated
Posted speed limits, school and construction zones, stopping and following distance.
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2. When in heavy traffic, the safest driving speed is:
Slower than the speed being driven by surrounding traffic.
The same speed being driven by surrounding traffic. ✓
Faster than the speed being driven by surrounding traffic.
Answer: B. The same speed being driven by surrounding traffic.
In heavy traffic, the safest speed is the same speed the surrounding traffic is driving. The handbook says directly that when traffic is heavy you should travel at the speed of other vehicles, because vehicles moving the same direction at the same speed are not likely to run into one another. It adds that you should drive with the flow of traffic if you can do so without going at an illegal or unsafe speed. That is why matching surrounding traffic is the correct choice, not picking a speed above or below the pack.
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. What is the number one cause of death and injury in a work zone?
Drivers speeding ✓
Slow drivers
Animals crossing the road
Answer: A. Drivers speeding
The number one cause is drivers speeding. The work zone section of the handbook names speeding as the leading source of injuries and deaths in roadway work zones. It tells you to watch the posted limit when you approach and drive through the zone, to keep checking your speedometer so your speed does not creep up on long construction stretches, and to slow further for bad weather, poor road conditions, or a worker close to the roadway. That is why speeding is the answer.
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.
6. While operating on a downgrade, you should brake until you reach a speed that is:
5 mph below your safe speed. ✓
10 mph below your safe speed.
15 mph below your safe speed.
Answer: A. 5 mph below your safe speed.
Brake until you are about 5 mph below your safe speed, then release the brakes. The handbook describes the braking technique for a long or steep downgrade. With the vehicle in the proper low gear, the engine does most of the slowing and the brakes are only a supplement. You apply the brakes enough to cause a clear slowdown, then release them once your speed is roughly five mph under your safe speed. When speed rises back to the safe speed, you repeat the process. That makes five mph below safe speed the release point.
7. 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.
8. 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.
Increase the amount of space between your vehicle and the vehicle in front of you. ✓
Make quick movements.
Answer: B. Increase the amount of space between your vehicle and the vehicle in front of you.
You should increase the amount of space between your vehicle and the vehicle in front of you. The handbook says that when someone is tailgating you, opening up room ahead helps you avoid sudden speed or direction changes. It also gives the tailgater an easier chance to get around you. The same passage says not to speed up and to avoid quick changes, so the safe response is to create more following distance in front rather than reacting sharply or going faster.
10. When entering traffic while operating a double or triple, a driver should:
Assume other drivers will make enough space for their vehicle to safely merge into traffic.
Wait for a gap that is large enough for their entire vehicle to safely merge into traffic. ✓
Decrease their following distance.
Answer: B. Wait for a gap that is large enough for their entire vehicle to safely merge into traffic.
Wait for a gap that is large enough for your whole vehicle to merge safely into traffic. The doubles and triples section of the handbook says these rigs take up more space than other commercial vehicles and cannot be turned or stopped suddenly. It tells you to make sure you have large enough gaps before entering or crossing traffic. The general driving section adds that because of slow acceleration and the space a large vehicle needs, you may need a much larger gap than a car would, and that you should be sure you can get all the way across before traffic reaches you.