PennDOT Commercial Driver's License 3

Question 1

When backing a tractor-trailer, a driver should primarily use which mirrors?

Accepted Answer

Both side mirrors and get out to check when uncertain

Answer

Only the right-side mirror

Answer

Only the left-side mirror

Answer

The rear-view mirror inside the cab

Question 2

What is the maximum allowable blood alcohol content (BAC) for CDL holders operating a commercial motor vehicle?

Accepted Answer

0.04%

Answer

0.08%

Answer

0.06%

Answer

0.02%

Question 3

Which of the following describes a 'runaway truck ramp' and when it should be used?

Accepted Answer

An escape ramp used when brakes fail on a downgrade

Answer

A designated area for overnight parking on steep grades

Answer

A weigh station bypass for trucks under the weight limit

Answer

A lane reserved for trucks traveling uphill

Question 4

What is the correct procedure for using the spring brakes when parking a CMV?

Accepted Answer

Chock the wheels and apply the parking brake

Answer

Apply the trailer brakes only

Answer

Leave the vehicle in gear without using the parking brake

Answer

Apply only the service brakes and turn off the engine

Question 5

Under federal hours-of-service rules that apply in Pennsylvania, property-carrying CDL drivers may not drive after being on duty for how many cumulative hours in 8 days?

Accepted Answer

70 hours

Answer

60 hours

Answer

80 hours

Answer

55 hours

Question 6

A CDL driver approaching a railroad crossing with no signals or gates must stop if the vehicle is carrying:

Accepted Answer

Chlorine, even in small amounts not requiring placards

Answer

Any cargo over 5,000 lbs

Answer

More than 10 passengers including the driver

Answer

Livestock in enclosed trailers

Question 7

What is the primary purpose of retarder systems (Jake brakes) on commercial vehicles?

Accepted Answer

To slow the vehicle and reduce wear on service brakes

Answer

To replace air brakes entirely on long downgrades

Answer

To improve acceleration in heavy traffic

Answer

To lock the drive wheels for emergency stops