When planning a trailer load, which arrangement helps reduce rollover risk?
Correct answer: Keep the load low and centered across the trailer
A lower, centered load reduces the tendency to tip. Load distribution does not remove the need to slow before curves.
Source: Washington Commercial Driver Guide, N/10/20; section 6.1.1, physical PDF 89, printed 6-1. ↗
A loaded trailer leans noticeably to one side before departure. Why is this a warning?
Correct answer: An off-center load makes rollover more likely
The guide warns against a load that makes the trailer lean. Correct load distribution and investigate the cause before driving.
Source: Washington Commercial Driver Guide, N/10/20; section 6.1.1, physical PDF 89, printed 6-1. ↗
What is the danger of a sudden lane change while pulling several trailers?
Correct answer: The rearward whipping motion can overturn a trailer
Abrupt steering can produce a crack-the-whip effect that grows toward the rear. This is a reason to steer smoothly, not a fixed rollover probability for every rig.
Source: Washington Commercial Driver Guide, N/10/20; section 6.1.2, physical PDF 89, printed 6-1. ↗
Which driving habit helps avoid a last-second swerve with a long combination?
Correct answer: Look well ahead and leave room for gradual corrections
A long view and adequate following space give time for controlled braking or gentle steering. Sudden corrections can destabilize a trailer.
Source: Washington Commercial Driver Guide, N/10/20; section 6.1.2, physical PDF 89, printed 6-1. ↗
You are driving a tractor without a semitrailer. What does the guide caution about this bobtail configuration?
Correct answer: It can be difficult to stop smoothly, so allow ample space
A bobtail tractor handles and brakes differently from a loaded combination. Do not assume that less total weight guarantees an easy, short stop.
Source: Washington Commercial Driver Guide, N/10/20; section 6.1.3, physical PDF 89, printed 6-1. ↗
Which trailer feature requires particular care at a raised railroad crossing?
Correct answer: Low clearance under the trailer or its landing gear
Low-slung equipment can hang up on a raised crossing. Assess clearance before entering rather than trying to power through a possible grounding point.
Source: Washington Commercial Driver Guide, N/10/20; section 6.1.4, physical PDF 90, printed 6-2. ↗
After hard braking, what observation may give the earliest warning that a trailer is starting to skid?
Correct answer: Its position begins changing unexpectedly in the mirrors
Check trailer alignment in the mirrors when braking hard. Waiting until it has swung far out of its lane makes recovery much harder.
Source: Washington Commercial Driver Guide, N/10/20; section 6.1.5, physical PDF 90, printed 6-2. ↗
A trailer has begun sliding because its wheels locked during braking. Why should you not use the trailer hand valve to straighten it?
Correct answer: More trailer braking can keep the wheels sliding instead of restoring traction
The guide says to release the braking that caused the trailer wheels to lock so they can regain traction. The trailer hand valve is not a device for pulling a skidding trailer straight.
Source: Washington Commercial Driver Guide, N/10/20; section 6.1.5, physical PDF 91, printed 6-3. ↗
In a slow, tight turn, the trailer's rear wheels pass inside the path of the tractor's front wheels. What is this called?
Correct answer: Off-tracking
Off-tracking means rear wheels follow a different, inner path around a corner. Plan the turn to keep those wheels clear of curbs and people.
Source: Washington Commercial Driver Guide, N/10/20; section 6.1.6, physical PDF 91, printed 6-3. ↗
When several trailers make a slow, tight corner, which rear wheels generally cut farthest inside?
Correct answer: Those on the last trailer
Each following unit adds to the off-tracking in this kind of turn. The last trailer needs attention even when the tractor has cleared the corner.
Source: Washington Commercial Driver Guide, N/10/20; section 6.1.6, physical PDF 91, printed 6-3. ↗
Why should a combination driver avoid swinging left before beginning a right turn?
Correct answer: It can invite a vehicle into the space along the rig's right side
An initial left swing can open a tempting gap on the right. Plan enough turning room without inviting another road user into the trailer's swept path.
Source: Washington Commercial Driver Guide, N/10/20; section 6.1.6, physical PDF 91, printed 6-3. ↗
From a straight tractor-semitrailer alignment, you want the trailer's rear to begin moving left while backing. Which initial steering action produces that movement?
Correct answer: Turn the top of the steering wheel to the right
To start a trailer backing turn, the steering input is opposite the desired direction of the trailer's rear. Follow and correct the trailer with subsequent small inputs under proper instruction.
Source: Washington Commercial Driver Guide, N/10/20; section 6.1.7, physical PDF 91, printed 6-3. ↗
