Maine BMV CDL General Knowledge Practice Test 6

  • Questions50
  • Correct to pass40
  • Passing score80%
  • Minimum age16 years

Minimum age: 16 years to operate a commercial motor vehicle, 21 years for a bus or hazardous materials

50 questions. Pick an answer to see if it is right and why; you need 40 correct answers to pass.

  1. 1. You are backing into a yard where electrical wires cross overhead. What is the main concern?

    Show answer

    Answer C: The wires may hang lower than the top of your vehicle

    Overhead space has to be checked like any other space around the vehicle, because wires and cables are often lower than they look from the cab.

  2. 2. What is the driver looking for when the exhaust system is inspected?

    Show answer

    Answer B: Loose, broken or missing pipes, brackets or clamps, and signs that exhaust is leaking

    A loose or leaking exhaust system can send carbon monoxide into the cab and can put hot gas against parts that will burn.

  3. 3. A commercial driver is convicted of two serious traffic violations within three years. What is the result?

    Show answer

    Answer D: Disqualification for 60 days

    Two serious traffic violations in a three year period bring a 60 day disqualification, and a third in the same period raises it to 120 days.

  4. 4. What happens to braking distance when speed is doubled?

    Show answer

    Answer C: It becomes about four times longer

    Braking distance grows with the square of speed, so doubling the speed multiplies both the braking distance and the force of an impact by about four.

  5. 5. What should you do with the previous driver vehicle inspection report before starting your trip?

    Show answer

    Answer B: Review it and confirm that listed defects were certified as repaired or as not needing repair

    Reviewing the last report and the carrier certification tells you whether reported defects have been corrected before you take the vehicle out.

  6. 6. A doctor prescribes you a medicine that can cause drowsiness. What should you do?

    Show answer

    Answer A: Tell the doctor what you drive and not drive while affected

    Both prescription and over the counter medicines can make a driver unsafe, so the medical professional must know the job and the driver must stay out of the seat while affected.

  7. 7. While double clutching, what goes wrong if you take too long between the two clutch movements?

    Show answer

    Answer A: Engine speed falls too far and the gear becomes hard or impossible to engage

    Double clutching only works while engine speed and road speed still match; a slow shift lets rpm drop away and the gear will not go in.

  8. 8. At what time of day do drowsy driving crashes occur most often?

    Show answer

    Answer A: Between midnight and 6 a.m.

    The body clock makes people sleepiest in the early morning hours, which is when most fatigue-related crashes happen.

  9. 9. After coupling, where should the fifth wheel release handle be?

    Show answer

    Answer A: In the locked position with the safety latch in place

    The handle must be pushed in and latched, because a handle left out means the jaws can open and release the trailer while you are driving.

  10. 10. Taking your eyes off the road for about five seconds at highway speed means traveling roughly how far unseen?

    Show answer

    Answer A: About the length of a football field

    At highway speed a five second glance away covers roughly 100 yards, which is far more road than any driver can afford to travel blind.

  11. 11. Your speedometer stops working during the pre-trip check. How should it be treated?

    Show answer

    Answer D: As a defect, because the driver cannot judge and control speed without it

    A working speedometer is required equipment, because judging speed by feel in a heavy vehicle is unreliable and speed governs stopping distance.

  12. 12. On packed snow, how much should a commercial driver reduce speed?

    Show answer

    Answer D: By about one half or more

    Packed snow costs far more traction than rain, so speed should be cut by half or more.

  13. 13. Besides allowing the move at all, what does an oversize load permit usually set out?

    Show answer

    Answer C: The route to be followed, the hours of travel allowed and the warning equipment needed

    Permits for oversize movements normally name the roads that may be used, restrict the times of travel, and list the flags, signs and escorts required.

  14. 14. You are asked to drive a truck loaded with enough hazardous materials to require placards. What must you have?

    Show answer

    Answer C: A hazardous materials endorsement on your commercial driver license

    Driving a vehicle that must be placarded requires the H endorsement, which involves a separate knowledge test and a security background check.

  15. 15. You pick up a trailer that another driver dropped in the yard. What must you do before pulling it?

    Show answer

    Answer B: Inspect it yourself, because you are responsible for the whole vehicle you drive

    Responsibility follows the driver who moves the vehicle, and a trailer that has stood in a yard may have lost air, developed a flat tire or been damaged.

  16. 16. Which steering system findings count as defects during the inspection?

    Show answer

    Answer C: Bent, loose or broken column parts, arms, drag links or tie rods, and missing nuts, bolts or cotter keys

    Every joint and fastener between the steering wheel and the tires carries the driver commands, so looseness or a missing retainer can end in a complete loss of steering.

  17. 17. You are taking a tightly curved highway exit ramp in a long combination. Where should the tractor be placed within the lane?

    Show answer

    Answer D: Toward the outside of the curve, leaving room for the trailer to track inside

    Because the trailer wheels cut to the inside of the curve, the tractor has to be kept out toward the outer edge so the trailer does not drop a wheel off the inside edge.

  18. 18. What is checked in step six of the seven-step method?

    Show answer

    Answer D: The turn signals and the stop lights, checked from outside the vehicle

    Step six returns to the cab to switch on the signal and stop lamps, then checks each one from outside, because those lamps are not lit during the earlier light check.

  19. 19. You want to check whether a tire on your truck is properly inflated. What is the correct method?

    Show answer

    Answer A: Measure the pressure with a tire gauge

    Only a tire gauge tells you the actual pressure; a tire can look and sound normal while being badly underinflated.

  20. 20. Apart from the legal duty, what is the main practical reason for a thorough pre-trip inspection?

    Show answer

    Answer A: It finds problems that could cause a breakdown or a crash before the vehicle is on the road

    A defect found in the yard is an inconvenience, while the same defect found at highway speed can be a crash, so the inspection is where problems are cheapest to fix.

  21. 21. A 60 foot combination traveling above 40 mph should hold how many seconds of following distance?

    Show answer

    Answer D: Seven seconds

    Six seconds cover the 60 feet of vehicle length, and one extra second is added because the speed is above 40 mph.

  22. 22. Why is driving much slower than the rest of the traffic dangerous?

    Show answer

    Answer B: Other drivers must keep passing you, which creates conflicts

    Traffic that has to work its way around you produces lane changes and closing speeds, which is why a large speed difference is itself a hazard.

  23. 23. Your vehicle begins to hydroplane on a wet road. What should you do?

    Show answer

    Answer B: Release the accelerator and push in the clutch so the wheels can turn freely and regain grip

    Hydroplaning tires are riding on water; slowing without braking lets them settle back onto the road and grip again.

  24. 24. You have stopped and a pedestrian is waiting to cross in front of your truck. Why should you not wave the person across?

    Show answer

    Answer C: Another driver may not stop, and your wave sends the person into danger

    You cannot control what drivers in the other lanes will do, so you should not invite a pedestrian into a lane you do not command.

  25. 25. What do you check about the fire extinguisher during the pre-trip?

    Show answer

    Answer C: That it is securely mounted, charged and that you know how to operate it

    An extinguisher must be held in its bracket, show a charged gauge and be understood by the driver, because a fire leaves no time to learn.

  26. 26. During the engine compartment check, which leaks are you looking for?

    Show answer

    Answer D: Fuel, coolant, engine oil, power steering fluid and battery fluid

    Every fluid in the compartment matters, because a fuel leak is a fire risk and a loss of coolant, oil, steering fluid or electrolyte can disable the vehicle.

  27. 27. Who must sign a driver vehicle inspection report?

    Show answer

    Answer D: The driver who prepared it

    The report is the driver statement about the condition of the vehicle at the end of the day, so the driver signs it.

  28. 28. Where is the yellow antilock brake malfunction lamp on a trailer, and what does it mean if it stays lit?

    Show answer

    Answer D: On the left side, at the front or rear corner, and it means the antilock function may not be working

    Trailers carry the yellow lamp on the left side, and a lamp that stays on after the bulb check means the antilock function may be lost even though the normal brakes still work.

  29. 29. What must a written driver vehicle inspection report cover at the end of the day?

    Show answer

    Answer C: Any defect or deficiency that would affect safety or could cause a mechanical breakdown

    The report identifies the vehicle and lists defects that affect safe operation or could lead to a breakdown, so they are repaired before the next trip.

  30. 30. You must steer hard around an obstacle at highway speed. What is the correct technique?

    Show answer

    Answer B: Avoid braking while turning, turn only as far as needed, and countersteer as soon as the obstacle is passed

    Braking during a hard steering input can lock the wheels and start a skid, and turning back at once keeps the vehicle from running off the far side of the road.

  31. 31. You are pulling away from the curb after a delivery. Why is a mirror check needed first?

    Show answer

    Answer B: A cyclist or a vehicle may be coming up alongside you

    Traffic and cyclists can arrive alongside a parked vehicle at any moment, so the mirrors must be checked immediately before pulling out.

  32. 32. Your brakes are starting to fade on a mountain downgrade and a sign shows an escape ramp one mile ahead. What should you do?

    Show answer

    Answer B: Plan to use the ramp instead of trying to reach the bottom

    Fading brakes on a grade only get worse, and the ramp exists precisely so a driver does not have to gamble on the rest of the descent.

  33. 33. Around a tractor-trailer, where are the blind areas that other drivers most often sit in unseen?

    Show answer

    Answer A: Along the right side and directly behind the trailer

    The blind areas to the right of the cab and behind the trailer are the largest, which is why other drivers should never linger there.

  34. 34. A vehicle carries placards on its front, rear and both sides. What is the main purpose of those placards?

    Show answer

    Answer C: To tell emergency responders and other people what hazard the cargo presents

    Placards warn everyone around the vehicle, especially emergency responders, about the kind of hazard the cargo presents.

  35. 35. Total stopping distance is made up of which parts?

    Show answer

    Answer A: Perception distance, reaction distance and braking distance

    The vehicle travels while the hazard is recognized, while the driver moves to the pedal, and again while the brakes slow the vehicle.

  36. 36. Your windshield washer reservoir is empty and rain and road spray are expected. What should you do?

    Show answer

    Answer D: Fill it before the trip, because you need the washers to keep the windshield clear

    Wipers alone smear the film of oil and grit thrown up by traffic, so the washers are part of keeping a usable view of the road.

  37. 37. A carrier operates commercial vehicles every day of the week. What weekly on-duty limit applies to its drivers?

    Show answer

    Answer A: 70 hours in 8 consecutive days

    The limit is 60 hours in 7 consecutive days for a carrier that does not run every day, and 70 hours in 8 consecutive days for one that does.

  38. 38. Under the federal hours of service rules, when must a property-carrying driver take a 30 minute break?

    Show answer

    Answer C: After 8 cumulative hours of driving time

    Driving is not allowed after 8 cumulative hours of driving time without at least a 30 consecutive minute interruption of driving.

  39. 39. Your brakes have failed on a downgrade and there is no escape ramp in sight. What is the best choice?

    Show answer

    Answer A: Steer into an open field or onto a side road that flattens out or climbs uphill

    A flat or uphill escape route uses gravity and rolling resistance to stop the vehicle; take it as soon as you see it, because the longer you wait the faster you go.

  40. 40. Why should a driver avoid stopping partway up a snow covered hill?

    Show answer

    Answer D: You may not get moving again and could slide backwards

    On a slippery grade the drive wheels may simply spin when you try to restart, leaving the vehicle stuck across the road or sliding back down it.

  41. 41. Which vehicle is exempt from the Maine commercial licensing requirement?

    Show answer

    Answer A: A registered farm truck bearing the letter F on its plate, used within 150 miles of the owner's farm

    Maine exempts farm trucks with an F registration plate operated by a farmer within 150 miles of the farm, along with firefighting apparatus, military operation and recreational vehicles for personal use.

  42. 42. What is the first step of the standard seven-step vehicle inspection?

    Show answer

    Answer C: A general overview of the vehicle, including the last inspection report

    The routine opens with a walk-up overview of the vehicle and a review of the previous inspection report so known defects are addressed first.

  43. 43. What should you check about the tire valve stems during the walkaround?

    Show answer

    Answer D: That the stems are not cut, cracked or leaking and the caps are in place

    A split stem or a missing cap lets air escape or lets dirt into the valve, and either one can flatten a tire between stops.

  44. 44. As a long vehicle goes around a corner, how do the rear wheels travel compared with the front wheels?

    Show answer

    Answer A: They follow a tighter path, closer to the inside of the turn

    The rear wheels off-track toward the inside of the turn, and the longer the vehicle the bigger the difference, which is why the front must swing wide enough to keep the rear off the curb.

  45. 45. An oncoming vehicle at night has bright headlights that are making it hard to see. What should you do?

    Show answer

    Answer B: Look toward the right edge of your lane and avoid looking directly at the lights

    Looking at the right edge of the road keeps your eyes off the glare while you stay in your lane; glare can leave you nearly blind for several seconds.

  46. 46. In dense city traffic you cannot see 12 seconds ahead because other vehicles block the view. What is the best response?

    Show answer

    Answer A: Slow down and open up more space in front of you

    When you cannot see far enough ahead, extra following distance buys back the reaction time that the blocked view has taken away.

  47. 47. Which exhaust system condition must be reported as a defect?

    Show answer

    Answer B: A section repaired by wrapping tape or patching material around the pipe

    Exhaust parts may not be patched with wrap or tape, because the repair does not contain the gas or the heat and it fails quickly in service.

  48. 48. Which brake lining condition must be reported?

    Show answer

    Answer C: Linings that are worn thin, loose, cracked or soaked with oil or grease

    Linings must have enough material left and must be securely attached and clean, because a thin, loose or contaminated lining cannot deliver its share of braking.

  49. 49. Why should you never shift gears while crossing railroad tracks?

    Show answer

    Answer A: You could miss the gear or stall and be stuck on the tracks

    A stalled or coasting vehicle on the tracks has no way to clear quickly, so choose the gear before the crossing and do not shift until you are across.

  50. 50. Which situations call for a mirror check in a commercial vehicle?

    Show answer

    Answer A: Every lane change, turn, merge and tight maneuver

    Mirrors must be checked regularly and always before, during and after any movement that changes the path of the vehicle.