You enter a highway work zone where the lane narrows and the pavement becomes uneven. What should guide your speed?
Correct answer: Leave time and room for workers, equipment and sudden path changes.
Work zones can combine uneven surfaces, narrow lanes, sharp turns and people near traffic. Reduce speed as needed and actively watch for changing hazards rather than assuming the normal road layout continues.
Source: Colorado Commercial Driver License Manual (06/15/23), Section 2; 2.8 Seeing Hazards; physical PDF page 33 (printed 33); reviewed September 14, 2026. ↗
A parked car's reverse lights come on as your truck approaches. What should you prepare for?
Correct answer: The car may back into your path.
Lights, moving front wheels and other visible activity can warn that a parked vehicle may enter your path. Treat them as a reason to prepare, not as proof that its driver has seen you.
Source: Colorado Commercial Driver License Manual (06/15/23), Section 2; 2.8 Seeing Hazards; physical PDF page 33 (printed 33); reviewed September 14, 2026. ↗
When should you enter a delivery destination and set up the navigation display?
Correct answer: Before driving, while safely parked.
Set up navigation and other cab controls before starting. If a later change requires attention that should be on driving, find a safe parking place before making it.
Source: Colorado Commercial Driver License Manual (06/15/23), Section 2; 2.9 Distracted Driving; physical PDF page 36 (printed 36); reviewed September 14, 2026. ↗
A carrier tells a driver to answer routine texts while driving a CMV. How does the federal texting rule apply to the carrier?
Correct answer: The carrier must not allow or require texting while driving.
49 CFR 392.80 prohibits a motor carrier from allowing or requiring a driver to text while driving. Dispatch needs must be handled without directing the driver to violate that rule.
Source: 49 CFR 392.80(b); eCFR title 49 displayed current through September 10, 2026; reviewed September 14, 2026. ↗
Your eyelids feel heavy and your truck has drifted toward the lane edge twice. What should you do?
Correct answer: Stop at the nearest safe place and get needed rest.
These are warning signs of fatigue. Do not wait for a crash or a planned stop to act. Get to a safe stopping place and rest before continuing; cab stimulation is not a substitute for sleep.
Source: Colorado Commercial Driver License Manual (06/15/23), Section 2; 2.11 Driving at Night / Fatigue; physical PDF page 39 (printed 39); 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. ↗
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. ↗
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. ↗
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. ↗
A bus is carrying passengers and is subject to 49 CFR 392.10 at a crossing with no applicable exception. Where must it stop relative to the tracks?
Correct answer: At least 15 feet but not more than 50 feet away.
The specified vehicles, including a bus transporting passengers, must stop within the 15-to-50-foot range and look and listen before crossing. Section 392.10 includes specific exceptions; the question excludes those situations.
Source: 49 CFR 392.10(a), (a)(1) and (b); eCFR title 49 displayed current through September 10, 2026; 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. ↗
Your truck is gaining speed on a steep descent because its brakes have failed. An escape ramp is ahead. What should guide your decision?
Correct answer: Use the available ramp rather than delay while speed builds.
Escape ramps are intended to help stop runaway vehicles. Know their locations and use an available ramp when brakes fail rather than letting the truck gather more speed while searching for a less inconvenient option.
Source: Colorado Commercial Driver License Manual (06/15/23), Section 2; 2.17.2 Stopping Quickly and Safely / Brake Failure on Downgrades; physical PDF page 46 (printed 46); reviewed September 14, 2026. ↗
A truck with hydraulic brakes loses pedal pressure. Which temporary response does the handbook describe as sometimes rebuilding enough pressure to help stop?
Correct answer: Pumping the hydraulic brake pedal.
For hydraulic pressure loss, pumping the pedal may build temporary pressure. This is not an instruction for air brakes or normal ABS operation. Stop safely and have the fault corrected; a temporarily firmer pedal does not make the truck serviceable.
Source: Colorado Commercial Driver License Manual (06/15/23), Section 2; 2.17.2 Hydraulic Brake Failure; physical PDF page 46 (printed 46); reviewed September 14, 2026. ↗
An ABS warning lamp remains on after its normal self-check or comes on while driving. What does that suggest?
Correct answer: An ABS fault may exist; normal brakes may still work, but service is needed.
A warning beyond normal startup behavior can indicate an ABS problem. With otherwise sound brakes, conventional braking remains, but ABS assistance may be lost. Have the problem serviced and do not confuse the normal initial lamp check with a fault.
Source: Colorado Commercial Driver License Manual (06/15/23), Section 2; 2.18 ABS Malfunction Lamps; physical PDF page 48 (printed 48); reviewed September 14, 2026. ↗
Why can locked tractor drive wheels during braking develop into a jackknife?
Correct answer: The trailer can push the tractor's sliding rear end sideways.
Locked drive wheels have little directional control. The trailer can push the tractor's rear out of line, folding the combination. Prevent wheel lock and use braking appropriate to the vehicle and conditions.
Source: Colorado Commercial Driver License Manual (06/15/23), Section 2; 2.19 Skid Control and Recovery; Figure 2.19; physical PDF page 49 (printed 49); reviewed September 14, 2026. ↗
Smoke is coming from inside a closed box trailer. Why should the driver keep the cargo doors shut?
Correct answer: Opening them can add oxygen and make the fire flare up.
Opening a burning cargo compartment can rapidly feed the fire. Keep the doors closed, stay clear and call emergency services, especially when the cargo may include hazardous materials.
Source: Colorado Commercial Driver License Manual (06/15/23), Section 2; 2.21.3 Keep the Fire from Spreading; physical PDF page 50 (printed 50); reviewed September 14, 2026. ↗
