New Mexico General Knowledge practice test
50 questions · 80% to pass · Required for every CDL applicant.
How to use this practice test
Read each question, click an answer, and the correct choice is highlighted with a short explanation referencing the underlying CDL Manual concept. Your live score appears at the top of the page. Refresh to reset.
This test runs entirely in your browser. Nothing is uploaded; no account is required. Pages refresh to a new randomized cut from the bank.
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1. When checking your vehicle, the engine should be off and the wheels chocked because:
Explanation. Chocking wheels and shutting down the engine prevents the vehicle from rolling away while you are underneath or alongside it.
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2. According to the FMCSA CDL Manual, most pre-trip inspections begin with which step?
Explanation. The CDL Manual lists "review last inspection report" as the first step in the seven-step pre-trip inspection. (Reinforcement variant — same underlying CDL Manual concept.)
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3. Most state DMV CDL handbooks state that when making a right turn in a large vehicle, you should:
Explanation. Stay in the right lane and watch the trailer; swinging left first invites a same-direction driver to squeeze in on your right. (Reinforcement variant — same underlying CDL Manual concept.)
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4. Per federal regulations, carbon monoxide poisoning may be a hazard if:
Explanation. A cracked exhaust manifold or rusted-through pipe can leak CO into the cab, causing drowsiness or death. (Reinforcement variant — same underlying CDL Manual concept.)
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5. Most state DMV CDL handbooks state that you should signal a lane change for at least:
Explanation. Signal early and continuously enough for surrounding traffic to see your intent. (Reinforcement variant — same underlying CDL Manual concept.)
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6. When taking the CDL knowledge exam, when checking your vehicle, the engine should be off and the wheels chocked because:
Explanation. Chocking wheels and shutting down the engine prevents the vehicle from rolling away while you are underneath or alongside it. (Reinforcement variant — same underlying CDL Manual concept.)
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7. When driving at night, you should adjust your speed so you can stop within:
Explanation. You must be able to stop within the distance you can see, which at night is the range of your low or high beam headlights.
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8. When taking the CDL knowledge exam, what does the term "perception distance" mean?
Explanation. Perception distance is the distance traveled while your brain identifies a hazard, typically about 1.5 seconds at highway speed. (Reinforcement variant — same underlying CDL Manual concept.)
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9. Most state DMV CDL handbooks state that when merging onto a highway, you should:
Explanation. Match traffic speed and yield; stopping is dangerous and can cause rear-end collisions. (Reinforcement variant — same underlying CDL Manual concept.)
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10. Most state DMV CDL handbooks state that a driver loses their CDL for life if convicted of:
Explanation. Using a CMV to commit a controlled-substance felony is grounds for a lifetime CDL disqualification. (Reinforcement variant — same underlying CDL Manual concept.)
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11. In real-world commercial driving, hours-of-service property-carrying drivers may drive a maximum of how many hours after 10 consecutive hours off duty?
Explanation. The federal HOS rule allows up to 11 hours of driving after 10 consecutive hours off duty. (Reinforcement variant — same underlying CDL Manual concept.)
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12. Per federal regulations, brake fade is caused by:
Explanation. Brakes lose effectiveness when overheated; this is why low gears are essential on grades. (Reinforcement variant — same underlying CDL Manual concept.)
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13. When driving down a long, steep grade, you should:
Explanation. Always select a low gear before descending so engine compression helps hold speed and brakes do not overheat.
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14. Per federal regulations, the 14-hour rule means a driver may not drive after the:
Explanation. After 14 consecutive hours on duty following 10 hours off, no further driving is allowed even if some of those 14 hours were not driving. (Reinforcement variant — same underlying CDL Manual concept.)
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15. In real-world commercial driving, hydroplaning is most likely when:
Explanation. Hydroplaning can occur at speeds as low as 30 mph if there is enough water and the tires cannot channel it away. (Reinforcement variant — same underlying CDL Manual concept.)
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16. When operating a CMV in interstate commerce, texting while driving a CMV is:
Explanation. Texting is banned for all CMV drivers under federal law. (Reinforcement variant — same underlying CDL Manual concept.)
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17. Experienced commercial drivers know that a driver may use a hand-held mobile phone while driving a CMV:
Explanation. Federal rules prohibit hand-held mobile phone use by CMV drivers except in emergencies. (Reinforcement variant — same underlying CDL Manual concept.)
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18. Aggressive driving by other motorists is best handled by:
Explanation. The safest response is to disengage and report when safe; never engage an aggressive driver.
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19. Most state DMV CDL handbooks state that when approaching a railroad crossing, you should:
Explanation. Always slow, look, listen, and prepare to stop. A full stop is required only for buses, hazmat, and certain placarded vehicles. (Reinforcement variant — same underlying CDL Manual concept.)
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20. When taking the CDL knowledge exam, carbon monoxide poisoning may be a hazard if:
Explanation. A cracked exhaust manifold or rusted-through pipe can leak CO into the cab, causing drowsiness or death. (Reinforcement variant — same underlying CDL Manual concept.)
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21. Brake fade is caused by:
Explanation. Brakes lose effectiveness when overheated; this is why low gears are essential on grades.
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22. When operating a CMV in interstate commerce, when driving at night, you should adjust your speed so you can stop within:
Explanation. You must be able to stop within the distance you can see, which at night is the range of your low or high beam headlights. (Reinforcement variant — same underlying CDL Manual concept.)
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23. When you double your speed, your stopping distance:
Explanation. Stopping distance increases roughly with the square of speed, so doubling speed nearly quadruples the distance.
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24. When taking the CDL knowledge exam, when checking lights during the pre-trip, you should turn the key on and:
Explanation. Have someone else watch, or turn lights on and off and walk around to verify each lamp is working. (Reinforcement variant — same underlying CDL Manual concept.)
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25. Per federal regulations, when making a right turn in a large vehicle, you should:
Explanation. Stay in the right lane and watch the trailer; swinging left first invites a same-direction driver to squeeze in on your right. (Reinforcement variant — same underlying CDL Manual concept.)
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26. When operating a CMV in interstate commerce, empty trucks need:
Explanation. Empty trucks have less traction and brakes designed for the loaded weight, so they can actually take longer to stop and lock up more easily. (Reinforcement variant — same underlying CDL Manual concept.)
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27. According to the FMCSA CDL Manual, a retarder helps the driver by:
Explanation. Retarders slow the vehicle without using service brakes, reducing brake wear and overheating risk. (Reinforcement variant — same underlying CDL Manual concept.)
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28. When making a right turn in a large vehicle, you should:
Explanation. Stay in the right lane and watch the trailer; swinging left first invites a same-direction driver to squeeze in on your right.
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29. Per federal regulations, when driving down a long, steep grade, you should:
Explanation. Always select a low gear before descending so engine compression helps hold speed and brakes do not overheat. (Reinforcement variant — same underlying CDL Manual concept.)
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30. When taking the CDL knowledge exam, a driver who is convicted of DUI in any vehicle while holding a CDL faces:
Explanation. A first DUI conviction in any vehicle disqualifies a CDL for at least one year. (Reinforcement variant — same underlying CDL Manual concept.)
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31. When merging onto a highway, you should:
Explanation. Match traffic speed and yield; stopping is dangerous and can cause rear-end collisions.
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32. In real-world commercial driving, a driver who is convicted of DUI in any vehicle while holding a CDL faces:
Explanation. A first DUI conviction in any vehicle disqualifies a CDL for at least one year. (Reinforcement variant — same underlying CDL Manual concept.)
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33. During a pre-trip inspection, which is the best way to handle a tire failure?
Explanation. Hard braking after a tire failure can cause loss of control. Hold the wheel firmly, ease off the throttle, and brake gently after slowing. (Reinforcement variant — same underlying CDL Manual concept.)
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34. During a pre-trip inspection, you must use low beams within how many feet of an oncoming vehicle?
Explanation. Switch to low beams within 500 feet of an oncoming vehicle to avoid blinding the other driver. (Reinforcement variant — same underlying CDL Manual concept.)
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35. Experienced commercial drivers know that aggressive driving by other motorists is best handled by:
Explanation. The safest response is to disengage and report when safe; never engage an aggressive driver. (Reinforcement variant — same underlying CDL Manual concept.)
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36. In real-world commercial driving, when making a right turn in a large vehicle, you should:
Explanation. Stay in the right lane and watch the trailer; swinging left first invites a same-direction driver to squeeze in on your right. (Reinforcement variant — same underlying CDL Manual concept.)
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37. When operating a CMV in interstate commerce, what does the term "perception distance" mean?
Explanation. Perception distance is the distance traveled while your brain identifies a hazard, typically about 1.5 seconds at highway speed. (Reinforcement variant — same underlying CDL Manual concept.)
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38. Most state DMV CDL handbooks state that you must use low beams within how many feet of an oncoming vehicle?
Explanation. Switch to low beams within 500 feet of an oncoming vehicle to avoid blinding the other driver. (Reinforcement variant — same underlying CDL Manual concept.)
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39. During a pre-trip inspection, empty trucks need:
Explanation. Empty trucks have less traction and brakes designed for the loaded weight, so they can actually take longer to stop and lock up more easily. (Reinforcement variant — same underlying CDL Manual concept.)
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40. According to the FMCSA CDL Manual, when checking your vehicle, the engine should be off and the wheels chocked because:
Explanation. Chocking wheels and shutting down the engine prevents the vehicle from rolling away while you are underneath or alongside it. (Reinforcement variant — same underlying CDL Manual concept.)
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41. According to the FMCSA CDL Manual, texting while driving a CMV is:
Explanation. Texting is banned for all CMV drivers under federal law. (Reinforcement variant — same underlying CDL Manual concept.)
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42. Experienced commercial drivers know that what is the standard color of a placard for a Class 2 (gases) hazardous material?
Explanation. Class 2 placards are red for flammable gas, green for non-flammable, and yellow/white for poison/oxygen subdivisions. (Reinforcement variant — same underlying CDL Manual concept.)
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43. When driving in fog, you should:
Explanation. High beams reflect off fog and reduce vision; low beams and slower speed are correct.
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44. You should NOT drive when taking which of these?
Explanation. Drowsiness-causing medications, even legal ones, can disqualify you from driving.
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45. The eye-lead time recommended for highway driving is at least:
Explanation. Look 12-15 seconds ahead so you can identify hazards in time to react smoothly.
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46. According to the FMCSA CDL Manual, total stopping distance equals:
Explanation. Total stopping distance is perception + reaction + braking distance combined. (Reinforcement variant — same underlying CDL Manual concept.)
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47. In real-world commercial driving, when approaching a railroad crossing, you should:
Explanation. Always slow, look, listen, and prepare to stop. A full stop is required only for buses, hazmat, and certain placarded vehicles. (Reinforcement variant — same underlying CDL Manual concept.)
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48. According to the FMCSA CDL Manual, when you double your speed, your stopping distance:
Explanation. Stopping distance increases roughly with the square of speed, so doubling speed nearly quadruples the distance. (Reinforcement variant — same underlying CDL Manual concept.)
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49. Most state DMV CDL handbooks state that when driving in fog, you should:
Explanation. High beams reflect off fog and reduce vision; low beams and slower speed are correct. (Reinforcement variant — same underlying CDL Manual concept.)
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50. Hours-of-service property-carrying drivers may drive a maximum of how many hours after 10 consecutive hours off duty?
Explanation. The federal HOS rule allows up to 11 hours of driving after 10 consecutive hours off duty.
About the General Knowledge exam
The General Knowledge exam is required for every Class A, B, and C CDL applicant. It covers vehicle inspection, basic control, shifting, backing, communicating with other drivers, distracted driving, fatigue, hazard perception, emergency maneuvers, skid control, accident procedures, hazardous materials awareness, and federal hours-of-service rules.
This New Mexico-specific edition uses the same federal source material every U.S. state adopts. The New Mexico MVD administers the actual exam at its service centers. Bring your CDL handbook for any last-minute reference; it’s free at every New Mexico MVD office.
Once you’re consistently scoring above 90% on this practice set, you’re well above the 80% required to pass the official New Mexico exam. Drill the questions you miss most often, then take the test cold once a day for a week leading up to your appointment.
Tips that actually work
- Read every answer choice before clicking. CDL questions are famous for "best answer" wording where two choices look right.
- Don’t memorize question text — learn the underlying rule. The DMV reshuffles wording constantly.
- Keep a list of the questions you miss. Re-drill them in isolation until you can’t miss them.
- Practice in short, frequent sessions. Two 20-minute sessions per day beats one two-hour cram.
What happens after I pass?
Passing the knowledge test earns you a Commercial Learner’s Permit (CLP). You must hold the CLP for at least 14 days before you can take the road skills test, and you must drive with a CDL-holding instructor in the cab during that period. Once you pass the road skills test, your CDL is issued.