The Texas General Knowledge CDL test measures the core safety knowledge used across commercial vehicle classes. It is not the Texas Commercial Rules test, an endorsement test, or an application guide.
Texas DPS lists Texas Commercial Rules first and General Knowledge second. Keep the subjects separate so practice results identify the correct weakness.
This guide stays focused on General Knowledge topics from the current handbook. For a broader application checklist, use Texas CDL Requirements.
Verified September 9, 2026: The Texas handbook states an 80% passing standard for each knowledge test. DPS does not promise a fixed question mix, so this guide no longer claims guaranteed counts by topic.
1. Build a General Knowledge Topic Map
Use the handbook to cover the complete subject instead of guessing how many questions a test session will draw from each area:
- 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. Alcohol, Controlled Substances and Consent Rules
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. Keep Texas Commercial Rules Separate
While the General Knowledge test is based on federal standards, Texas DPS adds some state-specific questions:
- Texas Commercial Rules: Texas DPS lists this as a separate subject before General Knowledge. For focused preparation, use our Texas Commercial Rules 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 weak areas revealed by practice: vehicle control, following distance, stopping distance, cargo securement, inspection and emergency procedures. Start the General Knowledge diagnostic, then verify every miss in DL-7C.
Frequently Asked Questions (FAQ)
How many questions are on the Texas General Knowledge CDL test?
The current Texas handbook requires 80% or better on each knowledge test. Texas DPS does not guarantee a fixed public question count or time limit for every session, so prepare by subject rather than by a memorized format.
Is the Texas General Knowledge test the same as Section 14?
No. General Knowledge covers core commercial-driving safety. Texas Commercial Rules is listed separately by DPS and includes state-specific material. Your complete assigned test list also depends on class, brakes and endorsements.
What score do I need to pass the Texas General Knowledge test?
You need 80% or better on each knowledge test. Ask DPS how a failed attempt affects your active application and next available test date; do not rely on a prep site’s same-day retest promise.
What topics should I focus on for the Texas General Knowledge test?
Cover vehicle control, inspection, space management, stopping distance, cargo securement and emergencies. No public DPS source guarantees that one topic will contribute a fixed number of live questions.