What to expect from your CDL knowledge test in 2020

Taking, and subsequently passing, your CDL test can be a difficult and nerve-wracking process. Nevertheless, with some solid studying and skills practice, obtaining your CDL will be a breeze. 

A CDL is required to operate any large, heavy, or placarded hazardous material vehicles in commerce. Additionally, there are three types of CDLs available, including Class A, B, and C.

With a Class A license, drivers can operate any combination of vehicles including tractor-trailers, tank vehicles, livestock carriers, and flatbeds, among others. The gross combination weight rating for this license is 26,001 or more lbs, provided the towed vehicle is heavier than 10,000 lbs. With this license, you can also operate Class B and Class C vehicles. 

Utilizing a Class B CDL, drivers can only operate a single vehicle, which includes straight trucks, various buses, box trucks, and tractor-trailers. The gross combination weight rating for this one is 26,001 or more lbs and can also tow a trailer that does not exceed 10,000 lbs. A Class B holder can also operate Class C vehicles, but not Class A. 

Finally, there’s the Class C CDL. With this license, drivers can operate a vehicle with the capacity to transport 16 or more occupants or hazardous materials. Vehicles that can be operated under this license include Small HazMat vehicles and passenger vans, among other vehicles. 

Depending on the CDL you’d like to get, your testing experience will differ greatly. However, you’ll still have two important factors involved in the process: a knowledge and skills test. Consequently, in this article, we’ll be breaking down what you should expect from your CDL knowledge test, and next week we’ll take a closer look at what you should expect from your CDL skills test. 

Knowledge Test

For the knowledge test, you’ll need to have a deep understanding of a plethora of factors in trucking including safety, operations, and controls among many others. 

According to the FMCSA, a basic knowledge test covers 20 general areas, but the test itself will contain 30 items. 

Here’s a breakdown of the basic knowledge that is required to pass your CDL knowledge test:

Safe operations regulations

Drivers must have knowledge on vehicles inspections, repair, and maintenance requirements, procedures for safe vehicle operations, the effects of fatigue and other health risks on the road, the types of vehicles and cargoes subject to specific requirements, and the effects of alcohol and drug use while operating a CMV.

Safe vehicle control systems

Drivers must have knowledge of the purpose and function of the controls and instruments commonly found on CMVs.

CMV safety control systems

Drivers must be knowledgeable on the proper ways to use a CMV's safety systems, including light, horns, mirrors, mirror adjustment, fire extinguishers, symptoms of improper operation revealed through instruments, operation characteristics, and diagnosing malfunctions. Drivers must also know the correct procedures to use safety systems in case of an emergency.

Basic control

Drivers must have knowledge on starting, warming up, and shutting down the engine, putting the vehicle in motion and stopping, backing in a straight line, and finally turning the vehicle.


Drivers must be knowledgeable on the key elements of shifting (like when to shift), shifting patterns and procedures, and the consequences of improper shifting.


Drivers must be knowledgeable on basic backing principles and rules as well as basic maneuvers when backing. 

Visual search

Drivers must have knowledge of various visual search techniques such as seeing ahead and to the sides, using mirrors, and finally seeing to the rear. 


Drivers must be knowledgeable about using their signals, communicating presence with horns or lights, and how the misuse of communications can affect them. 

Speed management

Drivers must understand how speed affects stopping distance, surface conditions, road shapes, visibility, and traffic flow.

Space management

Drivers must prove they have knowledge of the importance of space management, space cushions, space to the sides, and space for traffic gaps. 

Night operation

Drivers must prove an understanding of night driving factors, roadway factors, and vehicle factors.

Extreme driving conditions

Drivers must know basic information for dealing with bad weather, hot weather, and mountain driving.

Hazard perceptions

Drivers must have basic knowledge of road characteristics and road user activities.

Emergency maneuvers

Drivers must have knowledge of emergency actions such as evasive steering, emergency stops, off-road recovery, brake failures, and blowouts. 

Skid control and recovery

Drivers must be knowledgeable on the causes and major types of skids, as well as the procedures for recovering from skids.

Relationship of cargo to vehicle control

Drivers must understand the principles of handling cargo including the consequences of handling cargo improperly, driver responsibilities, federal and state laws, weight distribution, and methods of cargo securement. 

Vehicle inspections

Drivers must have an understanding of the importance of periodic inspections and repairs, the effects of undiscovered malfunctions, what safety-related parts to look for when inspecting vehicles, Pre-trip/enroute/post-trip inspection procedures, and reporting findings.

Hazardous Materials

Drivers must have a deep understanding of what constitutes hazardous material, classes of hazardous materials, labeling/placarding requirements, and the need for specialized training as a prerequisite for receiving the endorsement to transport hazardous cargo. 

Mountain Driving

Drivers must understand practices for mountain driving such as selecting a safe speed, selecting the right gear, and proper braking techniques.

Fatigue and awareness 

Drivers must be knowledgeable on the best practices for staying alert such as being prepared to drive, what to do to avoid fatigue, what to do when they’re tired on the road, and what to do when they become ill while driving. 

These twenty factors are basic factors that will be included in your CDL test. While exams may differ from state to state, the basic concepts that need to be understood will stay the same. While the knowledge test can be difficult, it should be fairly easy to pass if you’ve committed some time to study the CDL manual or taking online practice tests. 

So, how do you think you'll do when you take your CDL knowledge test? Let us know in the comments or on social media!

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