Free ID-CDL Practice Questions

Question 1

An Idaho applicant is 19 years old, has more than one year of licensed driving experience, and passes every required test for an air-braked Class A vehicle. Which restriction applies solely because of the applicant's age?

Accepted Answer

K, limiting commercial driving to intrastate operation

Answer

L, prohibiting operation of commercial vehicles equipped with air brakes

Answer

A restriction limiting the driver to vehicles that meet the Class B definition

Answer

No age-based restriction applies after all required tests are passed

Question 2

A 60-foot combination vehicle is traveling at 55 mph on a dry highway. Under the CDL following-distance rule, what minimum time gap applies before adding extra space for traffic, weather, or visibility?

Accepted Answer

7 seconds

Answer

6 seconds

Answer

8 seconds

Answer

4 seconds

Question 3

Cargo and tiedowns were checked before departure and again at mile 50. At mile 120, after 2 hours 15 minutes of driving, the driver brakes hard to avoid a collision. Which decision satisfies the cargo-inspection rule?

Accepted Answer

Reinspect at the first safe place; hard braking is a separate trigger

Answer

Wait until mile 150 because the scheduled distance interval controls

Answer

Wait until three driving hours unless the vehicle begins pulling to one side

Answer

Continue because the 50-mile inspection resets all event-based checks

Question 4

At highway speed, a steer tire suddenly blows. The vehicle pulls and vibrates, but the lane ahead remains clear. Which control sequence gives the driver the best chance of maintaining direction?

Accepted Answer

Grip the wheel firmly, avoid braking until stable, then slow gradually

Answer

Apply full service braking immediately and steer sharply toward the nearest shoulder

Answer

Ease off the accelerator and pump the service brakes rapidly while steering toward the shoulder

Answer

Shift to neutral and apply the parking brake in stages while holding the wheel straight

Question 5

Before a long downgrade, a driver selects the proper low gear and determines that 40 mph is the safe speed. As the vehicle reaches 40 mph, which braking pattern is appropriate?

Accepted Answer

Brake to about 35 mph, release, and repeat at 40 mph

Answer

Hold continuous light brake pressure from the top to the bottom of the grade

Answer

Allow speed to rise to 45 mph, then brake only until it returns to 40 mph

Answer

Use the trailer hand valve intermittently so the tractor brakes remain cool

Question 6

At one facility, a driver loads 700 pounds of nonbulk Class 3 material and 500 pounds of nonbulk Class 8 material. Both are Table 2 materials, and no other hazardous material is aboard. Which placarding option is permitted?

Accepted Answer

A DANGEROUS placard may replace the two specific Table 2 placards

Answer

No placards are required because neither hazard class alone reaches 1,001 pounds

Answer

Separate FLAMMABLE and CORROSIVE placards are mandatory, and DANGEROUS is prohibited

Answer

A CORROSIVE placard alone may represent the entire mixed load

Question 7

During a roadside stop, the driver of a hazardous-materials vehicle leaves the cab. Where may the shipping papers be kept so responders can locate them promptly?

Accepted Answer

In the driver-door pouch or on the driver's seat

Answer

On the passenger seat, clearly visible through the windshield

Answer

In an unlocked center console within reach from the driver's seat

Answer

In the sleeper berth beside the emergency-response guide

Question 8

A valve is damaged on a placarded cargo tank carrying Division 2.3 material, and a vapor cloud is drifting toward an occupied building. The driver has no approved respiratory protection. What is the best immediate response?

Accepted Answer

Move upwind, isolate the area, call responders, and provide the shipment details

Answer

Approach from upwind and close the valve before calling because the vapor is moving away from the driver

Answer

Drive the vehicle to an open area before establishing an exclusion zone or notifying responders

Answer

Keep the building occupied and wait for the carrier's emergency contact to authorize evacuation

Question 9

With the engine off, wheels chocked, parking brakes released, and the full service brake applied after pressure stabilizes, a tractor-trailer loses 5 psi in one minute. How should this result be interpreted?

Accepted Answer

It fails because the applied-leakage limit for a combination is 4 psi per minute

Answer

It passes because any loss below 6 psi per minute is acceptable for a combination vehicle

Answer

It passes as long as the low-air warning does not activate during the test

Answer

It is inconclusive unless the parking brakes are applied at the same time

Question 10

During an air-pressure fan-down check, the low-air warning first activates at 48 psi and the spring brakes begin applying at 32 psi. The test result shows that:

Accepted Answer

The low-air warning activates too late

Answer

The spring brakes apply too early

Answer

Both readings are within the acceptable ranges

Answer

Governor cut-out must be rechecked before either reading can be judged

Free ID-CDL Practice Questions

Domain 1: General Knowledge Test

Question 1

Question 2

Question 3

Question 4

Question 5

Domain 2: Air Brakes Test

Question 6

Question 7

Question 8

Domain 3: Combination Vehicles Test

Question 9

Question 10

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