Double
This endorsement is required if the driver will pull two or three trailers. To receive this endorsement, applicants must pass a test. The test consists of 20 multiple choice questions. To pass, the applicant must answer at least 16 questions correctly. Test questions come from the Illinois Commercial Driver’s License Study Guide. Questions come from chapters covering: Driving Safely, Air Brakes (if applicable), Combination Vehicles and Doubles and Triples. The Double/Triple endorsement can be used with the Class A CDL.
Number of Question
Passing Score
1. Hydroplaning is like:
Explanation
Hydroplaning is similar to water skiing: your vehicle's tires glide along the road on a film of water without having traction with the surface of the road.
2. If you are driving and your trailer begins to jackknife, you should not:
Explanation
If a trailer begins to jackknife, you should release the brakes and allow the trailer wheels to regain traction with the road. Do not apply the trailer hand brake in an attempt to straighten out the rig because it will only prolong the skid. The application of brakes is what caused the wheels to lock in the first place.
3. In a combination rig, it is best to make:
Explanation
When driving a combination vehicle, it is important to brake well in advance and look far ahead of your vehicle to avoid the need for sudden stops. Making habits of these actions will help you prevent your trailer from jackknifing.
4. A trailer will be most likely to swing around when:
Explanation
An empty trailer will require a longer stopping distance than a loaded trailer. Additionally, a trailer is most likely to swing out and strike other vehicles when it is lightly loaded or empty.
5. When traveling down a steep downgrade:
Explanation
On a downgrade, the braking effect of the engine should be your primary method of controlling speed. Shift down to a lower gear before starting down the hill and save the brakes for additional slowing or stopping that may be required by road or traffic conditions.
6. Which of the following is not an example of a driving hazard?
Explanation
Passing an accident scene can be hazardous because the people involved in the accident may not be watching traffic, and the scene itself may distract other passing drivers. Ice cream trucks can create hazardous conditions because they attract children who may not pay attention to nearby vehicles. Shoppers near the roadway are often paying attention to stores, not passing traffic.
7. A driver should always:
Explanation
