Getting your Class A permit in Texas requires passing four distinct tests, but the Texas General Knowledge CDL test is the “Big Boss.” It consists of 50 questions covering everything from engine mechanics to accident procedures.
Many students underestimate this exam because they focus too much on the unique “Section 14” test. However, if you fail General Knowledge, you leave the DPS empty-handed.
This 2026 guide dives deep into the specific topics the Texas Department of Public Safety (DPS) focuses on, ensuring you are ready for the Texas General Knowledge CDL test. For a broader practice experience, also try our Free CDL Practice Test.
1. Deconstructing the 50 Questions
The test is not random. It follows a specific structure based on the Federal CDL Manual. Here is where the questions come from:
- Vehicle Control (15-20 Questions): Braking techniques, shifting gears, steering, and skid recovery. This is the largest section.
- See & Be Seen (10-15 Questions): Mirror usage, communicating with lights and horn, night driving, and adjusting speed for visibility conditions.
- Hazards (10 Questions): Mountain driving, winter driving, railroad crossings, and aggressive drivers.
- Emergency Procedures (5-10 Questions): Fires, accident reporting, tire blowouts, and responding to hazardous conditions.
DPS Kiosk Strategy: On the Texas DPS computer, you have a “Skip” button. Use it. If you don’t know an answer, skip it. It will move to the end. If you answer 40 questions correctly before you run out of skips, the test ends automatically with a PASS. Do not waste time guessing on questions you are unsure about - skip them and come back.
Time limit: The Texas DPS gives you 60 minutes for the General Knowledge test. That is roughly 1 minute and 12 seconds per question. Most well-prepared test-takers finish in 25 to 35 minutes.
2. Critical Concept: “Implied Consent” in Texas
This is a huge focus area for the Texas General Knowledge CDL test. Texas has zero tolerance for alcohol in commercial vehicles.
- The Law: By holding a Texas CDL and driving on Texas roads, you have deemed to have given your consent to chemical testing (breath, blood, or urine) for alcohol or drugs.
- The Trap: You do not need to be convicted of a DWI to lose your license. Simply refusing the test results in an immediate 1-year disqualification of your CDL.
- Personal Vehicle: If you refuse a test while driving your personal car, you still lose your CDL privileges for 1 year. The DPS does not distinguish between vehicles when it comes to refusal.
- The BAC numbers you must know:
- 0.00% to 0.01%: Legal to drive a CMV.
- 0.02% to 0.039%: 24-hour Out-of-Service order. Not a DUI, but you cannot drive a truck for 24 hours.
- 0.04% and above: DUI conviction. 1-year CDL disqualification for first offense. 3 years if you were hauling HazMat. Lifetime ban for a second offense.
For more on drug and alcohol testing rules, see our DOT Drug Test Requirements guide.
3. Braking Distance: The Texas Formulas
You cannot guess these numbers. The DPS expects you to know the math.
Perception + Reaction + Braking
- Perception Distance: The distance your truck travels from the time your eyes see a hazard until your brain recognizes it. (1.75 seconds / approximately 142 feet at 55 mph).
- Reaction Distance: The distance traveled from the time your brain tells your foot to move until your foot hits the pedal. (0.75 seconds / approximately 61 feet at 55 mph).
- Braking Distance: The distance it takes for the brakes to actually stop the wheels once applied.
- Total Stopping Distance: At 55 mph on dry pavement, it takes about 450 feet (longer than a football field) to stop a fully loaded tractor-trailer.
Exam Tip: If a question on the Texas General Knowledge CDL test asks about stopping distance on wet roads, the rule is to double the braking distance. On packed snow, reduce your speed by at least half. On ice, reduce to a crawl and consider pulling over.
Following Distance Formula
The CDL manual uses a specific formula:
- 1 second for every 10 feet of vehicle length at speeds under 40 mph.
- Add 1 extra second at speeds above 40 mph.
- Add more distance for rain, snow, ice, or poor visibility.
Example: A 60-foot tractor-trailer traveling at 55 mph needs: 6 seconds (60 ft / 10) + 1 second (above 40 mph) = 7 seconds minimum following distance.
4. Cargo Securement Rules
Even if you aren’t a flatbedder, you must know these rules to pass General Knowledge.
- The “10-Foot” Rule: You need at least one tie-down for every 10 feet of cargo length.
- Minimums: No matter how small the item is, if it is not contained by the vehicle structure, it must have at least 2 tie-downs.
- Header Boards: You must know that a header board (or headache rack) is designed to protect the driver from cargo shifting forward during a crash or hard braking.
- Working Load Limit (WLL): Each tie-down has a rated capacity. The combined WLL of all tie-downs must be at least equal to half the weight of the cargo being secured.
- Inspection requirement: You must re-check cargo securement within the first 50 miles of a trip and then every 150 miles or every 3 hours (whichever comes first) thereafter.
5. Skid Control and Recovery
The DPS test always includes several questions on skid prevention and recovery.
- What causes a skid: Over-braking, over-steering, over-acceleration, or driving too fast for conditions. The rear wheels locking up is the most common skid type for tractor-trailers.
- Tractor jackknife: The tractor’s drive wheels lock and the tractor slides sideways, forming a V with the trailer. Release the brakes to regain traction.
- Trailer jackknife: The trailer wheels lock and the trailer swings out. Release the brakes and accelerate slightly to pull the trailer back in line.
- How to recover from ANY skid: Stop doing whatever caused it. If you were braking, release the brakes. If you were accelerating, ease off the throttle. Steer in the direction you want the front of the vehicle to go.
6. Texas-Specific Rules You Must Know
While the General Knowledge test is based on federal standards, Texas DPS adds some state-specific questions:
- Section 14 (Texas Special Requirements): This is a separate test with 20 questions covering Texas-specific laws. You must pass it in addition to General Knowledge to get your CLP. It covers topics like Texas lighting requirements, maximum vehicle height (14 feet 6 inches in Texas), and Texas registration rules. For a full breakdown, see our Texas CDL Manual Guide.
- Speed limits in Texas: Texas has some of the highest speed limits in the country. Many rural interstates allow 75 to 80 mph for passenger vehicles. But many trucking companies govern their trucks at 65 mph. The test may ask about the relationship between speed and stopping distance - doubling your speed quadruples your stopping distance.
- Texas weight limits: The standard federal 80,000 lb gross limit applies on interstates, but Texas allows higher weights on state roads with permits. See our CDL Weight Requirements guide for details.
7. Texas General Knowledge Practice Questions
These questions simulate the difficulty of the actual DPS exam.
The formula for the CDL test is: 1 second for every 10 feet of vehicle length. 40 ft / 10 = 4 seconds. Since you are under 40 mph, you do not add the extra second. At 45 mph, the answer would be 5 seconds (4 + 1 for speed above 40).
While many modern trucks are automatic, the test still covers manuals. You use the tachometer (RPMs) and road speed to know when to shift. Double clutching involves pushing the clutch in to shift to neutral, releasing it to rev-match, and pushing it in again to enter the new gear.
This is the "Zero Tolerance" safety rule. 0.04% is the limit for a DUI conviction, but any detectable amount (0.02%) warrants an immediate **24-hour Out-of-Service** order. You will not be arrested for DUI, but you cannot drive a commercial vehicle for 24 hours.
Federal cargo securement rules require an initial re-check within the first 50 miles, then every 150 miles or every 3 hours (whichever comes first) for the rest of the trip. This applies to all open-top and flatbed cargo.
The universal skid recovery rule: stop whatever caused the skid. If braking caused it, release the brakes. If accelerating caused it, ease off the throttle. Then steer in the direction you want the front of the vehicle to go. Never steer opposite the skid.
At 55 mph, total stopping distance for a loaded tractor-trailer includes perception distance (~142 feet), reaction distance (~61 feet), and braking distance (~247 feet). The total is approximately 450 feet - longer than a football field. On wet roads, this distance can double.
For more practice, check our CDL General Knowledge Practice Test and CDL Air Brakes Practice Test.
Conclusion
The Texas General Knowledge CDL test is a test of your memory and your understanding of physics. Do not rely on “common sense.” Study the numbers, understand the legal limits for alcohol, and master the pre-trip concepts.
Focus your study time on the high-yield areas: vehicle control (15-20 questions), following distance formulas, stopping distance math, cargo securement rules, and implied consent. These topics account for the majority of the exam. Practice with our Free CDL Practice Test until you score 90% or higher, then schedule your DPS appointment.
Frequently Asked Questions (FAQ)
How many questions are on the Texas General Knowledge CDL test?
The Texas General Knowledge CDL test consists of 50 multiple-choice questions. You must answer at least 40 questions correctly (80%) to pass. The test is administered on a computer kiosk at the DPS office and you have 60 minutes to complete it. Use the “Skip” button on questions you are unsure about - they move to the end of the test and you can come back to them.
Is the Texas General Knowledge test the same as Section 14?
No. The “General Knowledge” test covers federal safety rules applicable to all commercial vehicles - braking, cargo, following distance, skid control, and emergency procedures. “Section 14” (Texas Special Requirements) is a separate 20-question test specific to Texas state laws regarding lighting, vehicle height, registration, and other Texas-only regulations. You must pass both tests (plus Air Brakes and Combination Vehicles for Class A) to receive your Commercial Learner’s Permit in Texas.
What score do I need to pass the Texas General Knowledge test?
You need 80% to pass, which means at least 40 out of 50 questions correct. If you fail, you can retake the test the same day at some DPS offices, depending on wait times. Texas does not charge an additional fee for retaking the written test within the same application period, but policies vary by location. Study until you consistently score 90% on practice tests before attempting the real exam.
What topics should I focus on for the Texas General Knowledge test?
The highest-yield topics are vehicle control (braking techniques, shifting, steering, skid recovery), which accounts for 15-20 of the 50 questions. Following distance formulas and stopping distance math are guaranteed to appear. Cargo securement rules (tie-down requirements, inspection intervals) and implied consent laws (BAC limits, refusal penalties) are also heavily tested. Focus your study time on these areas rather than trying to memorize every detail of the manual.