A hands-free conversation leaves both hands available. Does that mean it cannot distract a CMV driver?
Correct answer: No. It can still take attention away from driving.
Distraction can be mental as well as physical. A hands-free arrangement does not guarantee full attention to driving, particularly during a demanding conversation or traffic situation.
Source: Colorado Commercial Driver License Manual (06/15/23), Section 2; 2.9 Distracted Driving; physical PDF page 35 (printed 35); reviewed September 14, 2026. ↗
Another driver makes an angry gesture and tries to provoke you. What is the safest response?
Correct answer: Avoid engaging and give the driver room to move away.
Do not turn another person's aggressive behavior into a confrontation. Keep your attention on safe driving, avoid retaliation and allow separation when you can do so safely.
Source: Colorado Commercial Driver License Manual (06/15/23), Section 2; 2.10 Aggressive Drivers / Road Rage; physical PDF page 37 (printed 37); reviewed September 14, 2026. ↗
Why should a driver avoid darkly tinted glasses when driving at night?
Correct answer: They reduce the light available for seeing hazards.
Night driving already offers less visual information. Dark lenses reduce available light further. Do not try to solve glare by making the whole scene darker.
Source: Colorado Commercial Driver License Manual (06/15/23), Section 2; 2.11.2 Driver Factors; physical PDF page 38 (printed 38); reviewed September 14, 2026. ↗
Headlight glare seems worse through a windshield with an oily film inside. What should you do before another night trip?
Correct answer: Clean both the inside and outside glass surfaces.
Dirt and film can scatter light and worsen glare. Cleaning inside and outside glass, along with mirrors and lights, helps preserve the limited visibility available at night.
Source: Colorado Commercial Driver License Manual (06/15/23), Section 2; 2.11 Driving at Night; physical PDF page 38 (printed 38); reviewed September 14, 2026. ↗
How should interior cab lighting be managed during night driving?
Correct answer: Keep it low enough to avoid glare while instruments remain readable.
Bright interior lighting can interfere with outside vision. Keep instruments readable without unnecessary cab glare, and maintain attention to the road.
Source: Colorado Commercial Driver License Manual (06/15/23), Section 2; 2.11 Night Driving Procedures; physical PDF page 40 (printed 40); reviewed September 14, 2026. ↗
A truck's headlamps are dirty and one is poorly aimed. What is the right response before driving at night?
Correct answer: Clean the lamps and have their aim corrected.
Dirty or misaligned headlamps reduce useful road illumination and may create glare for others. Correct their condition rather than compensating with unsafe following or inappropriate beam use.
Source: Colorado Commercial Driver License Manual (06/15/23), Section 2; 2.11 Vehicle Factors; physical PDF page 39 (printed 39); reviewed September 14, 2026. ↗
Oncoming high beams make it hard to see. Where should you direct your attention?
Correct answer: Toward the right side of your lane, without staring at the lights.
Avoid looking directly into bright oncoming lamps. Use the right side of your lane as a guide while continuing to monitor your path and adjusting speed for the visibility you actually have.
Source: Colorado Commercial Driver License Manual (06/15/23), Section 2; 2.11 Night Driving Procedures; physical PDF page 40 (printed 40); reviewed September 14, 2026. ↗
Which headlight setting generally gives better visibility in fog?
Correct answer: Low beams, because high beams reflect more light back toward you.
High beams reflect off fog and can worsen the driver's view. Use low beams and an appropriate reduced speed; better lighting does not remove the need for a safe visibility margin.
Source: Colorado Commercial Driver License Manual (06/15/23), Section 2; 2.12 Driving in Fog; physical PDF page 40 (printed 40); reviewed September 14, 2026. ↗
Why is following the vehicle ahead's taillights an unreliable way to navigate dense fog?
Correct answer: That vehicle may stop or leave the roadway without you realizing it.
Do not blindly follow lights through fog. The other vehicle may be stopped or may have left the roadway. Maintain your own awareness of the road and a safe distance.
Source: Colorado Commercial Driver License Manual (06/15/23), Section 2; 2.12 Driving in Fog; physical PDF page 40 (printed 40); reviewed September 14, 2026. ↗
Before entering a stretch of very dense fog, you can safely reach a truck stop. What is the safer option if visibility is inadequate?
Correct answer: Wait at the truck stop until conditions improve.
When possible, avoid driving in dense fog by waiting in a safe location such as a truck stop or rest area. A roadside stop can expose the truck to vehicles whose drivers cannot see it in time.
Source: Colorado Commercial Driver License Manual (06/15/23), Section 2; 2.12 Driving in Fog; physical PDF page 40 (printed 40); reviewed September 14, 2026. ↗
Which preparation helps keep the windshield usable in freezing conditions?
Correct answer: Check the defroster, wipers and freeze-protected washer supply.
Winter preparation includes a working defroster, suitable wipers and washer fluid protected against freezing. Do not start relying on equipment before confirming it can keep your view clear.
Source: Colorado Commercial Driver License Manual (06/15/23), Section 2; 2.13 Driving in Winter; physical PDF page 40 (printed 40); reviewed September 14, 2026. ↗
Snow and ice cover a truck's steps and handholds. What should happen before using them?
Correct answer: Clear them so you have secure footing and a reliable grip.
Winter inspection includes clearing snow and ice from steps and handholds. Secure access reduces the risk of a fall; jumping or relying on eventual melting is not a sound substitute.
Source: Colorado Commercial Driver License Manual (06/15/23), Section 2; 2.13 Vehicle Checks; physical PDF page 41 (printed 41); reviewed September 14, 2026. ↗
Why must a driver monitor engine temperature when using a winter front or radiator cover?
Correct answer: Restricting airflow too much can cause the engine to overheat.
A winter cover changes cooling airflow. Too much restriction can overheat an engine even in cold weather, so use the proper equipment and monitor temperature.
Source: Colorado Commercial Driver License Manual (06/15/23), Section 2; 2.13 Vehicle Checks / Radiator; physical PDF page 41 (printed 41); reviewed September 14, 2026. ↗
A railroad crossing has a crossbuck but no active lights or gates. What does the lack of active warnings mean?
Correct answer: You must use the signs and your own observation to assess trains.
A passive crossing does not actively warn you with lights or gates. Observe and obey the signs, look and listen, and meet any stopping requirement that applies to your vehicle or load.
Source: Colorado Commercial Driver License Manual (06/15/23), Section 2; 2.15 Railroad-Highway Crossings / Passive Crossings; physical PDF page 42 (printed 42); reviewed September 14, 2026. ↗
Railroad red warning lights begin flashing while the gate is still upright. What should you do?
Correct answer: Stop before the tracks rather than trying to beat the gate.
Stop when the crossing's red lights begin flashing; do not wait for the gate to block the lane. Remain stopped until the gates are up, the lights have stopped and it is safe to cross.
Source: Colorado Commercial Driver License Manual (06/15/23), Section 2; 2.15.2 Warning Signs and Devices; physical PDF page 43 (printed 43); reviewed September 14, 2026. ↗
One train has just cleared a crossing with several tracks. What must you check before proceeding?
Correct answer: That no other train is approaching and the crossing warnings permit travel.
A train on one track may hide a train on another. Check all tracks in both directions and keep obeying the lights and gates; the first train's departure alone does not establish a clear crossing.
Source: Colorado Commercial Driver License Manual (06/15/23), Section 2; 2.15.3 Double Tracks Require a Double Check; physical PDF page 43 (printed 43); reviewed September 14, 2026. ↗
Before a long mountain descent, which combination should determine a truck's safe speed?
Correct answer: Weight, grade length and steepness, road conditions and weather.
A safe descent speed depends on the vehicle and the actual grade and conditions. A speed that worked on another hill or for another vehicle may not be suitable for this descent.
Source: Colorado Commercial Driver License Manual (06/15/23), Section 2; 2.16.1 Select a Safe Speed; physical PDF page 44 (printed 44); reviewed September 14, 2026. ↗
Why can poorly adjusted brakes make overheating more likely on a downgrade?
Correct answer: Some brakes do too little work, overloading the others.
When some brakes are not doing their share, the others must work harder. That can overheat them and accelerate fade. Correct adjustment and condition matter before starting a descent.
Source: Colorado Commercial Driver License Manual (06/15/23), Section 2; 2.16.3 Brake Fading or Failure; physical PDF page 45 (printed 45); reviewed September 14, 2026. ↗
In the handbook's downgrade example, a suitable low gear is selected and the safe speed is 40 mph. When applying the described snub-braking method, at about what speed are the brakes released?
Correct answer: 35 mph, about 5 mph below that selected safe speed.
The handbook describes applying enough braking for a definite slowdown, then releasing around 5 mph below the chosen safe speed and repeating as needed when that safe speed is reached. Forty mph is the example, not a universal mountain speed; proper gear selection and actual conditions remain essential.
Source: Colorado Commercial Driver License Manual (06/15/23), Section 2; 2.16.4 Proper Braking Technique; physical PDF page 45 (printed 45); reviewed September 14, 2026. ↗
A tractor has functioning ABS but its trailer does not. Is the tractor's ABS still useful?
Correct answer: Yes. It can help retain tractor control even without trailer ABS.
ABS can still offer benefits on the part of the combination that has it. Tractor ABS does not make an unequipped trailer an ABS trailer, so avoid assuming identical anti-lock protection throughout the combination.
Source: Colorado Commercial Driver License Manual (06/15/23), Section 2; 2.18 ABS on the Tractor or Trailer; physical PDF page 48 (printed 48); reviewed September 14, 2026. ↗
