ELDT 1 — Questions and Answers

Question 1: If you have to drive off the road in an emergency, you should:

If at all possible, keep one pair of wheels on the pavement.
As soon as your car has stopped, try to remain on the shoulder.
Do not apply the brakes until you have reduced your speed.
All of the above. (Correct answer)

Correct answer: All of the above.

If you have to drive off the road in an emergency, it's crucial to follow several safety guidelines. Keeping one pair of wheels on the pavement, if possible, helps maintain some control and stability. Once your vehicle has stopped, remaining on the shoulder is safer than re-entering traffic immediately. Most importantly, do not apply the brakes until you have significantly reduced your speed, as sudden braking on an unstable surface can cause loss of control or a rollover.

Question 2: Air brakes operate when the brake pedal is pushed:

solely when ABS is functioning.
following roughly fifteen seconds
right away.
after a little interval. (Correct answer)

Correct answer: after a little interval.

Air brakes do not engage instantaneously when the pedal is pushed; there is a slight delay, known as 'lag time.' This interval is due to the time it takes for air pressure to travel through the system and fully reach the brake chambers to apply the brakes. Drivers must account for this delay, especially when braking at higher speeds, to ensure safe stopping distances.

Question 3: It is customary to indicate your intention to turn at least ____ before making a lane change.

250 feet
75 feet
100 feet (Correct answer)
50 feet

Correct answer: 100 feet

It is customary and legally required in many jurisdictions to signal your intention to turn or change lanes at least 100 feet before executing the maneuver. This provides other drivers with sufficient warning of your intentions, allowing them enough time to react safely and adjust their speed or position. This advance notice is crucial for preventing potential collisions and maintaining smooth traffic flow.

Question 4: How do you move forward on a hill without rolling back?

Before releasing the right foot from the brake, partially engage the clutch; use the parking brake if needed. (Correct answer)
Before you have enough engine power to prevent rolling back, release the parking brake.
Even if you have to roll back a little, put your foot down on the throttle pedal.
None of the above

Correct answer: Before releasing the right foot from the brake, partially engage the clutch; use the parking brake if needed.

To move forward on a hill without rolling back, you should partially engage the clutch (find the friction point) while your right foot is still on the brake. As the clutch begins to engage and the engine starts to pull, smoothly release the brake and simultaneously apply the accelerator. For steep hills or when more control is needed, using the parking brake to hold the vehicle while engaging the clutch and accelerator is an effective method to prevent rollback.

Question 5: In the event that the air brake system's safety relief valve opens:

The valve is working well.
This will give the brakes greater force.
There's a problem. (Correct answer)
this will supply more power to the drive wheels.

Correct answer: There's a problem.

The safety relief valve in an air brake system is designed to open only if the air pressure in the system exceeds a safe operating limit, typically around 150 psi. If this valve opens, it indicates that the air compressor is not cutting off properly or there is another malfunction causing excessive pressure buildup. This is a serious problem that requires immediate attention, as over-pressurization can damage components and lead to brake failure.

Question 6: When you stop midway on your journey to rest, make sure to check:

indicators of potential problems.
heater, defroster and windshield wiper blades.
tires, brakes, lights and cargo securement devices. (Correct answer)
exhaust pipes missing.

Correct answer: tires, brakes, lights and cargo securement devices.

When stopping midway on a journey to rest, it's crucial for a commercial driver to perform a thorough inspection of critical vehicle components. This includes checking the tires for proper inflation and damage, inspecting the brakes for wear or issues, verifying all lights are functioning, and ensuring that cargo securement devices are still tight and holding the load effectively. These checks are vital for safety and compliance throughout the remainder of the trip.

Question 7: It is necessary to fully empty the air tanks in order to remove:

air.
the radiator cap.
carbon monoxide.
water and oil. (Correct answer)

Correct answer: water and oil.

Air brake systems accumulate water and oil in the air tanks due to condensation and compressor operation. It is necessary to fully empty (drain) the air tanks regularly to remove this accumulated water and oil. Failure to do so can lead to corrosion, freezing in cold weather, and contamination of the air lines and brake components, which can impair brake performance and cause system damage.

Question 8: Holding on to the emergency brakes requires:

dynamic pressure.
hydraulic pressure.
air pressure.
mechanical force. (Correct answer)

Correct answer: mechanical force.

Emergency brakes (also known as parking brakes) in most vehicles, especially commercial vehicles, operate using mechanical force. They typically engage a cable system that physically applies brake shoes or pads to the wheels, holding the vehicle stationary. Unlike service brakes which use hydraulic or air pressure, the emergency brake relies on a direct mechanical linkage to maintain its hold.

Question 9: There are no spring brakes on older trailers. Should the air supply disappear:

The emergency brakes will not be functioning. (Correct answer)
It will stop the trailer normally.
The ABS won't function correctly.
All of the above.

Correct answer: The emergency brakes will not be functioning.

Older trailers without spring brakes rely solely on air pressure to keep the service brakes released. If the air supply disappears, there is no mechanism to apply the emergency brakes automatically. This means the trailer would not have a fail-safe braking system, making it unable to stop itself in an air loss situation.

Question 10: The fastest way to know that your trailer is beginning to skid is:

by examining your rearview mirror.
by releasing the brakes.
by checking the jackknife sensor.
by hearing squeaking noises from the wheels. (Correct answer)

Correct answer: by hearing squeaking noises from the wheels.

When a trailer begins to skid, the tires lose traction and often produce a distinct squealing or squeaking sound. This auditory cue is typically the earliest and most direct indicator of a skid, allowing a driver to react quickly. While rearview mirrors can show a developing jackknife, the sound often precedes visible signs, especially in the initial stages of a skid.

Question 11: Out of the following, which is NOT a hazard?

A cardboard box on the road
Work zones
An escape ramp (Correct answer)
A freeway/highway exits that go downhill

Correct answer: An escape ramp

An escape ramp is a safety feature designed to help runaway vehicles stop safely when their brakes fail, particularly on long, steep downgrades. It is a protective measure, not a hazard itself. Cardboard boxes, work zones, and steep downhill exits are all potential dangers that require increased driver awareness and caution.

ELDT 1

If you have to drive off the road in an emergency, you should: