Connecticut General Knowledge CDL Practice Test
25 realistic General Knowledge practice questions for Connecticut CDL applicants. Required for: All CDL applicants (Class A, B, and C). Official test: 50 questions, 40 correct to pass.
Question 1 of 25 · Vehicle Dynamics
Empty trucks:
-
A.
Always stop more quickly than loaded trucks
-
B.
Have less traction because there is less weight on the drive axles
-
C.
Can take curves at higher speeds safely
-
D.
Are not affected by wind
Correct answer: B.
Empty trucks have reduced traction on drive axles and require greater stopping distances than loaded trucks.
Question 2 of 25 · Adverse Conditions
When you have to drive into the sun and visibility is reduced, what should you do?
-
A.
Use sunglasses and lower the visor
-
B.
Use only your high beams
-
C.
Maintain your normal speed
-
D.
Speed up to get past the area
Correct answer: A.
Use sunglasses and the visor and slow down. Reduced visibility increases stopping distance.
Question 3 of 25 · Basic Control
You should use the parking brake:
-
A.
Only when parking on hills
-
B.
Whenever you leave the vehicle
-
C.
Only when leaving the engine running
-
D.
Only on slick surfaces
Correct answer: B.
Always set the parking brake whenever you leave your vehicle, regardless of the surface or grade.
Question 4 of 25 · Adverse Conditions
What should you do when your vehicle hydroplanes?
-
A.
Brake hard immediately
-
B.
Release the accelerator and push in the clutch
-
C.
Steer sharply
-
D.
Accelerate to regain control
Correct answer: B.
Release the accelerator and push in the clutch. Don't use the brakes — let the wheels regain traction.
Question 5 of 25 · Communication
When should you check your mirrors?
-
A.
Only before changing lanes
-
B.
Frequently, to know what is around your vehicle
-
C.
When parking only
-
D.
Only at intersections
Correct answer: B.
Check mirrors regularly to know what is happening around your vehicle.
Question 6 of 25 · Night Driving
When meeting an oncoming vehicle at night, you should:
-
A.
Look directly at the headlights
-
B.
Look toward the right side of the road
-
C.
Switch to high beams
-
D.
Increase speed
Correct answer: B.
Look toward the right side of the road to avoid being blinded by oncoming headlights.
Question 7 of 25 · Inspection
What is the minimum tread depth for non-steering axle tires?
-
A.
1/32 inch
-
B.
2/32 inch
-
C.
4/32 inch
-
D.
6/32 inch
Correct answer: B.
Federal regulations require at least 2/32 inch on non-steering tires.
Question 8 of 25 · Backing
You should always try to park:
-
A.
So that you will have to back when leaving
-
B.
So that you can pull forward when leaving
-
C.
On the right shoulder of any highway
-
D.
Without using the parking brake
Correct answer: B.
Park so that you can pull forward to leave. Backing should always be avoided when possible.
Question 9 of 25 · Emergency Maneuvers
What should you do if your brakes fail on a downgrade?
-
A.
Pump the brakes vigorously
-
B.
Look for an escape ramp or open area to slow down
-
C.
Shift into neutral
-
D.
Turn off the engine
Correct answer: B.
If brakes fail, look for an escape ramp or a route that will slow your vehicle without endangering others.
Question 10 of 25 · Hazard Awareness
Hazardous conditions exist when there are:
-
A.
Pedestrians and bicyclists
-
B.
Children and elderly drivers
-
C.
Distractions and bad weather
-
D.
All of the above
Correct answer: D.
Hazards include other road users, weather, distractions, and changing road surfaces.
Question 11 of 25 · Inspection
What is the most important reason for doing a vehicle inspection?
-
A.
To meet DOT requirements
-
B.
Safety for yourself and others
-
C.
To save fuel
-
D.
To avoid roadside inspections
Correct answer: B.
Safety is the most important reason. A defective vehicle puts you, your cargo, and others at risk.
Question 12 of 25 · Cargo
How can you tell if your vehicle is overloaded?
-
A.
It rides higher than normal
-
B.
It handles differently from when properly loaded
-
C.
It uses less fuel
-
D.
It accelerates faster
Correct answer: B.
Overloaded vehicles handle poorly — they accelerate slower, take longer to stop, and are harder to steer.
Question 13 of 25 · Cargo
Which is true about cargo securement?
-
A.
Drivers are responsible for inspecting cargo
-
B.
Cargo only needs to be inspected at the start of a trip
-
C.
Securement is the shipper's sole responsibility
-
D.
Once strapped, cargo never needs re-checking
Correct answer: A.
Drivers must inspect cargo and its securement at the start of the trip and re-check periodically.
Question 14 of 25 · Speed Management
When you double your speed, your stopping distance is multiplied by approximately:
-
A.
Two
-
B.
Three
-
C.
Four
-
D.
Six
Correct answer: C.
Stopping distance grows with the square of speed. Doubling speed roughly quadruples the distance needed to stop.
Question 15 of 25 · Backing
The most important hand signal you and a helper should agree on is:
-
A.
Speed up
-
B.
Stop
-
C.
Turn left
-
D.
Back straight
Correct answer: B.
Always agree on a clear stop signal before backing. The helper must be able to stop you instantly.
Question 16 of 25 · CDL Rules
What is the legal blood alcohol concentration (BAC) limit for CDL drivers?
-
A.
0.08%
-
B.
0.05%
-
C.
0.04%
-
D.
0.02%
Correct answer: C.
Federal CDL law sets the BAC limit at 0.04%, half the limit for non-commercial drivers.
Question 17 of 25 · Inspection
When inspecting your vehicle, the engine should be:
-
A.
Running with the hood open
-
B.
Off, with the parking brake set, before starting checks under the hood
-
C.
Idling in gear
-
D.
Warm but turned off only on hills
Correct answer: B.
Set the parking brake, turn off the engine, and chock the wheels before checking under the hood.
Question 18 of 25 · Speed Management
The total stopping distance of a CDL vehicle includes:
-
A.
Perception, reaction, and braking distance
-
B.
Only braking distance
-
C.
Following distance and brake lag
-
D.
Only the distance traveled while braking
Correct answer: A.
Total stopping distance is the sum of perception distance, reaction distance, brake lag, and braking distance.
Question 19 of 25 · Emergency Maneuvers
Stab braking is used:
-
A.
Only on slippery roads
-
B.
When you must stop quickly with non-ABS brakes
-
C.
Whenever you stop
-
D.
Only on downgrades
Correct answer: B.
Stab braking is an emergency technique used with non-ABS brakes: apply brakes fully, release when wheels lock, then reapply.
Question 20 of 25 · Inspection
The proper way to test the service brake on a vehicle is to:
-
A.
Pump the pedal three times
-
B.
Push the brake pedal firmly while moving about 5 mph
-
C.
Put the parking brake on
-
D.
Listen for air leaks
Correct answer: B.
Move the vehicle forward at about 5 mph and apply the brake firmly. The vehicle should not pull to either side.
Question 21 of 25 · Driver Wellness
What should you do when an aggressive driver confronts you?
-
A.
Make eye contact and respond
-
B.
Try to escape the situation safely and avoid eye contact
-
C.
Slow down to teach a lesson
-
D.
Speed up and pass
Correct answer: B.
Avoid engagement, give space, do not make eye contact, and report the behavior.
Question 22 of 25 · Emergency Maneuvers
Which of the following is a sign of tire failure?
-
A.
A loud "bang" sound
-
B.
Vibration or thumping
-
C.
Heavy steering or fishtailing
-
D.
All of the above
Correct answer: D.
A bang, vibration, heavy steering, or fishtailing can all indicate tire failure.
Question 23 of 25 · ABS
ABS:
-
A.
Allows you to drive faster
-
B.
Lets you brake hard without losing steering control
-
C.
Means you don't have to use safe driving techniques
-
D.
Eliminates the need to inspect brakes
Correct answer: B.
ABS preserves steering during emergency braking but does not shorten stopping distance.
Question 24 of 25 · Speed Management
Engine brakes (Jakes) should not be used:
-
A.
On dry pavement at highway speed
-
B.
On slippery roads while loaded or empty
-
C.
When descending a steep grade
-
D.
Heading toward a long downhill
Correct answer: B.
Avoid engine brakes on slippery roads — they can cause the drive wheels to lose traction.
Question 25 of 25 · Emergency Equipment
What three kinds of emergency equipment must you have in your vehicle?
-
A.
Spare tire, fuses, and reflective triangles
-
B.
Fire extinguisher, spare fuses (if equipped), and warning devices
-
C.
First aid kit, water, and flares
-
D.
Tool kit, fuel can, and flag
Correct answer: B.
You must have a fire extinguisher, spare electrical fuses (if equipped), and warning devices for stopped vehicles.
About the General Knowledge Test
The General Knowledge test covers safe vehicle inspection, basic vehicle control, shifting gears, communicating, controlling speed, controlling distance, seeing hazards, distracted driving, aggressive drivers, communicating with other drivers, night driving, driving in fog, winter driving, hot weather driving, mountain driving, driving emergencies, anti-lock braking systems, skid recovery, accident procedures, fires, alcohol and other drugs, hazardous materials awareness, and staying alert and fit to drive. Every commercial driver in the United States must pass this test before any other CDL endorsement can be added.
The Connecticut Department of Motor Vehicles administers this knowledge test as part of its commercial driver license program. To earn the CDL General Knowledge on your Connecticut CDL, you need to score at least 40 out of 50 on the official version.
Topics covered on this practice test
- Inspection: 4 questions
- Emergency Maneuvers: 3 questions
- Speed Management: 3 questions
- Adverse Conditions: 2 questions
- Backing: 2 questions
- Cargo: 2 questions
- Vehicle Dynamics: 1 question
- Basic Control: 1 question
- Communication: 1 question
- Night Driving: 1 question
- Hazard Awareness: 1 question
- CDL Rules: 1 question
- Driver Wellness: 1 question
- ABS: 1 question
- Emergency Equipment: 1 question
How to use this practice test
- Read each question carefully. CDL questions are written precisely — small wording differences matter.
- Click "Show Answers & Explanations" only after answering every question. Don't peek mid-test.
- Read the explanation for every question, even ones you got right. The reasoning is more important than the answer.
- Repeat the test until you score 100%. The questions are deterministic per state, so you can track your improvement over multiple sessions.
- Move on to the other endorsement tests for Connecticut until you're ready for the official exam.
Tips specific to the General Knowledge test
The General Knowledge test is the foundation of every CDL. Topics include vehicle inspection, basic control, shifting, communicating, controlling speed, controlling space, hazard perception, distracted driving, night driving, fog, winter, hot weather, mountain driving, emergencies, anti-lock brakes, skid recovery, accident procedures, fires, alcohol, hazardous materials awareness, and staying alert. Most failures come from speeding through inspection-related questions; slow down and read carefully.
Other practice tests for Connecticut