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. Each question has four possible answer choices. Test questions come from the Indiana Commercial Driver License Manual. 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. To check the automatic transmission fluid level in some vehicles, the vehicle:
Explanation
For some vehicles, you may need to leave the engine running to be able to check its automatic transmission fluid level.
2. When using a turn signal, you should not:
Explanation
Always signal well ahead of a turn or lane change. Signal continuously until you have completed the turn or lane change, then be sure to cancel the signal so you do not confuse other drivers.
3. Hydroplaning usually occurs:
Explanation
In places where water collects on the road, it is possible for a vehicle to hydroplane. Low tire pressure or worn tire tread makes this more likely to happen. If there is enough water on a road surface, hydroplaning can occur at speeds as low as 30 mph.
4. What is the only way to sober up after drinking?
Explanation
The liver removes alcohol from the body at a fixed rate that cannot be increased through tricks like drinking coffee or taking a cold shower. The only way to sober up after drinking is to wait for the alcohol to be removed from your system.
5. Check ____ to ensure that the air in your vehicle's air braking system flows to all tires.
Explanation
Check the air brakes on a double or triple combination during your normal pre-trip inspection. After air pressure has reached a normal level, push in the red trailer air supply knob to send air to the emergency lines. Use the trailer hand brake to send air to the service line, then open the rear shut-off valve. If air is escaping through the valve, you will know that the entire system is charged.
6. If a truck's Anti-Lock Braking System (ABS) is not working:
Explanation
If an ABS system fails, the vehicle will still have normal braking function. The driver should continue to drive and brake as they normally would.
7. Before a vehicle with dual air brakes is driven, pressure of at least ____ should be built up in both braking systems.
Explanation