Combination Vehicles Practice Test | California 2025 #1

Train for FREE online with our California CDL combination vehicle test. The official exam test consists of several obligatory parts, with all of them checking your knowledge of different blocks of road rules. If you need to obtain a CA combination license in 2025, practice as much as possible. Free sample tests published on our website will help you check and improve your knowledge and boost your grades. Please bear in mind that DMV requirements for issuing a combination license may vary from state to state.

Number of Question 20

Passing Score 17

Number of Tests 20

1 . To find out if a vehicle that was built before 1998 has an Anti-Lock Braking System (ABS), you can:

Pump the air brakes to activate the ABS.

Look into the back of the fifth wheel.

Check for wheel speed sensors coming from the back of the brakes.

If you are operating a vehicle built before 1998 and are unsure if the trailer has an Anti-Lock Braking System (ABS), you can check under the trailer for wheel speed sensors coming from the back of the brakes.

2 . Avoid needing to make sudden lane changes by:

Using your horn to encourage other drivers to move out of your lane.

Only driving slower than the posted speed limit.

Watching the road ahead while driving.

Making a sudden lane change can be dangerous when driving a combination vehicle. Avoid the need to make a sudden lane change by looking down the road for upcoming obstacles that will require you to change lanes.

3 . Before beginning a trip, you should:

Leave the service line valve open.

Remove the relay valves.

Close the emergency line valve.

Before a trip, you should ensure that air reaches all air brakes on all trailers by opening up the rear emergency line and service line shut-off valves and listening for escaping air. Close both shut-off valves before beginning to drive.

4 . When entering or crossing traffic while driving a combination vehicle, it is especially important that you:

Sound your horn.

Make sure there is a large enough gap for your vehicle.

Expect other drivers to make room for your vehicle.

Combination vehicles require more space on the road than other vehicles. When entering or crossing traffic while driving a combination vehicle, it is especially important that there is a large enough gap in traffic for you to safely do so.

5 . Maintain a following distance of at least ____ for every 10 feet of your vehicle if you are traveling at a speed under 40 mph.

One second

Two seconds

Three seconds

At speeds below 40 mph, you should allow at least one second of following distance for every 10 feet of your vehicle. Follow the same formula when traveling at faster speeds, then add one additional second to your following distance. Remember that larger vehicles require more space to stop than smaller vehicles.

6 . Pull out the trailer air supply control to test:

The parking brake.

The trailer emergency brakes.

The trailer service brakes.

The landing gear.

Be sure to test the trailer emergency brakes before beginning a trip. After ensuring that the trailer rolls freely, you can test the emergency brakes by pulling out the trailer air supply control, or placing it in the "emergency" position. Pull forward slightly with the tractor and make sure the trailer does not move.

7 . If you press the tractor air supply control and your trailer's spring brakes do not release, you should:

Inspect the air line connections.

Activate the Anti-Lock Braking System.

Turn the engine off and on again.

It is important that all of a vehicle's equipment is in proper working condition before beginning a trip. If a trailer's spring brakes do not release when you push in the tractor air supply control, you should make sure the air line connections are properly attached and sealed.

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2025 California | Frequently Asked Questions

To acquire a CDL Hazmat endorsement in California, you must first have a Commercial Driver's License (CDL). Then, pass the Hazardous Materials (Hazmat) Knowledge Test at a DMV office. After passing, complete a Transportation Security Administration (TSA) background check. Once cleared, take the Hazmat endorsement form to DMV to add the endorsement to your CDL.

To obtain a CDL Hazmat license in California, you need to have a valid Commercial Driver's License (CDL). You must also pass the Hazardous Materials (Hazmat) endorsement knowledge test, provide a valid Transportation Security Administration (TSA) security threat assessment (background check), and complete fingerprinting. Training on handling hazardous materials is also required.

When applying for a CDL Hazmat endorsement in California, you need to provide your current valid Commercial Driver's License (CDL), proof of U.S. citizenship or lawful permanent residency (birth certificate, passport, or green card), and a completed Medical Examination Report Form. You'll also need to pass a TSA background check and provide fingerprints.

Yes, there is a dedicated written test for the CDL Hazmat endorsement in California. This test is designed to evaluate your knowledge about the rules and regulations related to the transportation of hazardous materials. It covers topics such as loading and unloading, bulk packaging, and emergency response procedures. You must pass this test to obtain the endorsement.

The written test for the CDL Hazmat endorsement covers a variety of subjects related to hazardous materials, including: recognition and identification of hazardous materials, compliance with safety regulations, understanding shipping papers, placarding requirements, loading and unloading procedures, handling emergencies and incidents, and the rules for transporting specific types of hazardous materials.

Yes, there are extra charges associated with acquiring a CDL Hazmat endorsement. In California, you must pay a $30 testing fee. Additionally, fingerprinting for the TSA background check costs approximately $86.50. Please note that these fees are subject to change and it's advisable to check the current rates with your local DMV office.

Yes, obtaining a CDL Hazmat endorsement does require a background check and security clearance. This is mandated by the Transportation Security Administration (TSA) and involves fingerprinting and checking for any disqualifying criminal offenses. The goal is to ensure the safety and security of hazardous materials transportation. It's necessary to pass this check to receive the endorsement.

Yes, specialized training and certification are required for the CDL Hazmat endorsement. Applicants must pass a written test regarding the transportation of hazardous materials. Additionally, they must undergo a TSA background check. These requirements ensure that drivers have the necessary knowledge and skills to safely transport hazardous materials.

No, you cannot legally transport hazardous materials without a valid CDL Hazmat endorsement in California. This endorsement is required to ensure the driver's understanding of safety precautions and procedures for transporting hazardous materials. Driving without it can lead to serious legal consequences including fines and suspension of your commercial driver's license.

Yes, you can add the CDL Hazmat endorsement to your current CDL license. You don't need to apply for a new license. However, you must pass a written Hazmat knowledge test and undergo a TSA background check. Once these steps are completed, the Hazmat endorsement can be added to your existing CDL.