Your trip paperwork and a heavy tool are lying loose beside the pedals. What should you do before moving?
Correct answer: Stow them securely so they cannot obstruct the controls
Loose cab objects can interfere with pedals or strike someone during a sudden stop. Secure them before starting.
Source: Washington Commercial Driver Guide, N/10/20; section 2.1.5, physical PDF 35, printed 2-7. ↗
Your truck's safety belt latches, but the webbing is badly frayed. Which conclusion is correct?
Correct answer: The belt needs attention; latching alone does not make it sound
The inspection includes the mounting, adjustment, latch and webbing. A ripped or frayed belt is not made serviceable just because its buckle clicks.
Source: Washington Commercial Driver Guide, N/10/20; section 2.1.5, physical PDF 32, printed 2-4. ↗
A helper is about to guide your truck into a bay. What must the two of you agree on before backing?
Correct answer: A clear set of signals, especially the signal to stop
Both people need to understand the signals before the truck moves. The helper must be visible to the driver; a stop signal is particularly important.
Source: Washington Commercial Driver Guide, N/10/20; section 2.2.4, physical PDF 36, printed 2-8. ↗
The road becomes icy while your truck's speed retarder is engaged. What does the CDL guide advise?
Correct answer: Turn the retarder off because drive wheels may skid
Retarding force at the drive wheels can exceed available grip on slippery roads. The guide directs drivers to switch it off on wet, icy or snow-covered surfaces.
Source: Washington Commercial Driver Guide, N/10/20; section 2.3.4, physical PDF 38, printed 2-10. ↗
You complete a right turn in a truck whose indicator does not cancel automatically. What should you do next?
Correct answer: Cancel it so others are not misled about your next move
A signal left on after the turn sends a false message. Keep it on through the turn, then cancel it once the maneuver is complete.
Source: Washington Commercial Driver Guide, N/10/20; section 2.5.1, physical PDF 39, printed 2-11. ↗
When estimating total stopping space, why is the distance traveled before touching the brake important?
Correct answer: Perception and reaction travel are added to braking travel
The truck continues moving while the driver notices a hazard and reacts. Total stopping space includes that travel as well as the braking distance.
Source: Washington Commercial Driver Guide, N/10/20; section 2.6.1, physical PDF 41, printed 2-13. ↗
After a dry spell, light rain has just begun on the highway. Why can the surface be particularly slick?
Correct answer: Water mixes with oil and residue already on the pavement
Initial rain can mix with accumulated road deposits before heavier rain washes them away. Reduce speed and allow more room.
Source: Washington Commercial Driver Guide, N/10/20; section 2.6.2, physical PDF 42, printed 2-14. ↗
For a 60-foot combination at 55 mph in good conditions, what baseline gap follows the guide's length-and-speed rule?
Correct answer: At least 7 seconds
Allow one second per ten feet, then add one second above 40 mph: six plus one is seven. Conditions can require a still larger gap.
Source: Washington Commercial Driver Guide, N/10/20; section 2.7.1, physical PDF 44, printed 2-16. ↗
Why is swinging left before starting a wide right turn hazardous in a large truck?
Correct answer: A following driver may enter the opening along your right side
The opening and apparent leftward movement can invite a vehicle onto your right. Plan the turn to protect that space and monitor it carefully.
Source: Washington Commercial Driver Guide, N/10/20; section 2.7.6, physical PDF 46, printed 2-18. ↗
You need directions for a new delivery location. When is the best time to enter the route into your navigation system?
Correct answer: Before moving, with the truck safely parked
Set up the route before driving. If you later need to change it, find a safe place to stop instead of dividing attention in traffic.
Source: Washington Commercial Driver Guide, N/10/20; section 2.9.6, physical PDF 51, printed 2-23. ↗
In dense fog, why should you not simply follow a pair of taillights as your guide to the roadway?
Correct answer: They may belong to a vehicle stopped off the road
Lights ahead may be on the shoulder or outside the travel lane. Do not substitute another vehicle's position for your own assessment of the road.
Source: Washington Commercial Driver Guide, N/10/20; section 2.12, physical PDF 55, printed 2-27. ↗
After water enters brake drums, how can braking performance change?
Correct answer: Brakes may weaken, grab or apply unevenly
Wet brakes can behave unpredictably, including weakness or uneven application. Avoid deep water and do not assume normal braking remains available.
Source: Washington Commercial Driver Guide, N/10/20; section 2.13.2, physical PDF 56, printed 2-28. ↗
On a dry downgrade, the truck is in the proper low gear and 35 mph is your selected safe speed. Under the guide's braking technique, when do you release an application begun at 35 mph?
Correct answer: After slowing to about 30 mph
The described technique supplements engine braking: make a definite slowdown to about five mph below the selected safe speed, release, and repeat when speed returns to that safe value.
Source: Washington Commercial Driver Guide, N/10/20; section 2.16.4, physical PDF 60, printed 2-32. ↗
Which benefit should you expect from functioning ABS during hard braking?
Correct answer: Reduced wheel lockup and improved ability to retain control
ABS manages wheel lockup. It may help maintain steering and stability without necessarily shortening the stop.
Source: Washington Commercial Driver Guide, N/10/20; section 2.18, physical PDF 63, printed 2-35. ↗
Everyone has escaped a burning truck. Where should you gather while calling 911?
Correct answer: At least 100 feet away and well clear of traffic
USFA advises moving everyone at least 100 feet from a burning vehicle and away from traffic. Stay out and let emergency responders handle the fire.
Source: US Fire Administration, Vehicle Fire Safety; evacuation distance and emergency notification. ↗
With accessible cargo and no exception, you have driven 3 hours but only 110 miles since the last cargo recheck. What is required?
Correct answer: Reexamine the load now; the three-hour trigger has been reached
For applicable trucks, recheck when duty status changes, after three driving hours or after 150 miles, whichever comes first. The mileage limit does not postpone a time-based check.
Source: 49 CFR 392.9(b)(3); duty change, 3 hours or 150 miles, whichever first. ↗
When arranging heavy and light freight, which layout generally lowers rollover risk?
Correct answer: Place the heavier freight low and the lighter freight above it
Keeping heavy cargo low reduces the center of gravity. High stacks and heavy freight on top increase instability in curves or evasive moves.
Source: Washington Commercial Driver Guide, N/10/20; section 3.2.3, physical PDF 73, printed 3-2. ↗
Under the general article-securement rule, what minimum aggregate working load limit is needed for an 8,000-pound article?
Correct answer: 4,000 pounds
The aggregate WLL minimum is half the article's weight: 8,000 divided by two. Count and arrangement rules must also be met, and a tiedown's contribution depends on how it is attached.
Source: 49 CFR 393.106(d); aggregate working-load limit, general article rule. ↗
A 12-foot article is properly blocked against forward movement. Under the general rule, what is its minimum tiedown count, assuming no special rule applies?
Correct answer: Two tiedowns
Properly blocked articles require at least one tiedown per ten feet or fraction. Twelve feet therefore needs two; adequate blocking, strength and attachment remain necessary.
Source: 49 CFR 393.110(c); blocked 12-foot article, no special-method exception. ↗
Why does a refrigerated trailer carrying hanging meat call for particular caution on a curved exit ramp?
Correct answer: The suspended load can be unstable and has a high center of gravity
Hanging cargo can be unstable and top-heavy. Enter curves slowly and avoid abrupt control changes that can disturb the load.
Source: Washington Commercial Driver Guide, N/10/20; section 3.4.2, physical PDF 74, printed 3-3. ↗
