Texas CDL — General Knowledge Exam Simulation
50 questions · 40 correct to pass. You won't see any feedback until you finish — just like the real test.
Texas CDL — General Knowledge questions with answers
20 sample questions from the Texas CDL — General Knowledge question bank — each with the correct answer, a short explanation, and the section of the official handbook it comes from.
1. If your wheels drift off the pavement onto the shoulder, you should:
Correct answer: Ease off the accelerator, hold the wheel firmly, and steer back gently when it is safe
Do not brake hard or jerk the wheel back. Ease off the accelerator, hold the wheel firmly, and when it is safe steer gently back onto the pavement.
2. How many driver licenses may a commercial driver legally hold?
Correct answer: Only one
You may hold only one license. Having more than one is illegal and can lead to disqualification.
3. When you inspect dual tires, which condition is unsafe?
Correct answer: The two tires are touching each other
Dual tires must not touch each other or any part of the vehicle. Tires that rub can overheat and fail, so they must be spaced correctly.
4. Under federal rules, how may a commercial driver use a mobile phone while driving?
Correct answer: Only hands-free, without holding or reaching for the phone
FMCSA bans holding or reaching for a hand-held phone while driving a commercial vehicle. Only hands-free use, with the phone within reach and operated by a single touch, is allowed.
5. If another driver is tailgating you, the safest response is to:
Correct answer: Open up more space ahead so you can slow down gradually
Open up more space in front of you so you can slow down gradually instead of braking hard. Do not speed up, and avoid sudden moves or brake-light tricks that could cause a rear-end crash.
6. Before you start across railroad tracks, you must be sure that:
Correct answer: You have room to drive completely across without having to stop
Never start across the tracks unless you have enough room to get completely across without stopping. Do not let traffic ahead trap your vehicle on the tracks.
7. Over-the-counter and prescription medicines:
Correct answer: Can impair driving, so you must read the labels and warnings
Many legal medicines, such as cold and allergy pills, can cause drowsiness or otherwise impair driving. Read the labels and do not drive if a medicine warns against operating machinery.
Source: Texas CDL Handbook — Other Drugs
8. When you park a commercial vehicle and leave the cab, you should:
Correct answer: Apply the parking brake and secure the vehicle so it cannot roll
Apply the parking brake whenever you leave the vehicle, and on a grade turn the wheels and use chocks as needed so the vehicle cannot roll.
Source: Texas CDL Handbook — Parking
9. A sign for a 'runaway truck ramp' tells drivers that:
Correct answer: There is an escape ramp ahead for vehicles that have lost their brakes
A runaway truck ramp is an escape ramp ahead where a vehicle that has lost its brakes can be brought to a safe stop. Note its location as you start down a long grade.
10. You should turn on your four-way emergency flashers when:
Correct answer: When you are stopped at the roadside or must drive unusually slowly
Use your four-way flashers when you are stopped or parked at the roadside, and whenever you must drive so slowly that you become a hazard to others.
11. When turning left at an intersection with oncoming traffic, a commercial driver must:
Correct answer: Yield to oncoming traffic and allow extra time to finish the turn
You must yield to oncoming traffic when turning left, and allow for the extra time and space your large vehicle needs to complete the turn safely.
12. After you steer hard to swerve around a sudden hazard, you must be ready to:
Correct answer: Countersteer, turning the wheel back the other way, to regain your lane
Once you have passed the hazard you have to countersteer, quickly turning the wheel back the other way, or you may run off the road or roll over. Do not brake while turning sharply.
13. Entry-Level Driver Training (ELDT) is generally required before a person can:
Correct answer: Get a first Class A or B CDL, upgrade a CDL, or obtain certain endorsements
ELDT must be completed before obtaining a Class A or Class B CDL for the first time, upgrading an existing CDL, or getting a first school bus, passenger, or hazardous materials endorsement.
14. Cargo held down with tie-downs must have at least:
Correct answer: One tie-down for every 10 feet of cargo, and no fewer than two total
There must be at least one tie-down for every 10 feet of cargo, and no fewer than two tie-downs no matter how short the load. Their total working load limit must be at least half the cargo's weight.
15. A posted speed limit tells a commercial driver:
Correct answer: The maximum legal speed in ideal conditions, which may be too fast when conditions are poor
The posted limit is the maximum legal speed under ideal conditions. In rain, fog, heavy traffic, or on a downgrade, a safe speed for a large vehicle is often well below the limit.
16. Why should you not fully trust a posted bridge or overpass clearance height?
Correct answer: Repaving or packed snow can make the real clearance lower than the posted height
Repaving or packed snow can reduce the actual clearance, and the weight of a load lowers some vehicles. If you are not sure your vehicle will fit, slow down and find another route.
17. Which vehicles must stop at every railroad crossing, even when no train is in sight?
Correct answer: Buses carrying passengers and vehicles hauling placarded hazardous materials
Buses carrying passengers and vehicles hauling placarded hazardous materials must stop at railroad crossings. Most other commercial vehicles slow, look, and listen but need not always stop.
18. Under 'implied consent' laws, by driving a commercial vehicle you have agreed to:
Correct answer: Submit to testing for alcohol or drugs when required
Implied consent means that by driving you have already consented to be tested for alcohol or drugs. Refusing a required test brings a disqualification, just like a failed test.
19. If you must stop your vehicle along the road, you should:
Correct answer: Pull as far off the road as you can, turn on your flashers, and set out warning devices
Pull as far off the road as possible, turn on your four-way flashers, and set out warning devices so other drivers can see your stopped vehicle in time.
20. When you plan to turn, you should signal:
Correct answer: Early, well before you begin the turn
Signal early, well before the turn, so other drivers know your plans in time. Keep signaling through the turn and make sure the signal cancels afterward.