The official source for Texas CDL study is the Texas Commercial Motor Vehicle Drivers Handbook (DL-7C). The current linked edition was revised in March 2026. This page is a reading map for that handbook—not an application checklist and not a second Texas Commercial Rules practice page.
Verified September 9, 2026: Download a fresh copy before studying because Texas DPS can replace the PDF without changing its URL.
How the Texas CDL Manual Is Organized
The Texas CDL manual follows the same general structure as the federal model handbook that the FMCSA provides to all 50 states. Sections 1 through 13 are nearly identical whether you are testing in Austin or Albany. Here is the layout:
- Section 1 — Introduction: Who needs a CDL, federal classifications (Class A, B, C), and exemptions.
- Section 2 — Driving Safely: Vehicle inspection, basic control, shifting, space management, night driving, and hazard perception.
- Section 3 — Transporting Cargo: Weight distribution, load securement, and blocking/bracing.
- Section 5 — Air Brakes: System components, inspection procedures, and the antilock braking system requirements.
- Section 6 — Combination Vehicles: Coupling, uncoupling, and inspecting the fifth wheel and glad hands. Required for Class A.
- Sections 7 through 10 — Endorsements: Doubles/Triples, Tank Vehicles, Passenger, and Hazardous Materials.
- Section 11, 12, 13 — The Skills Tests: Vehicle inspection test, basic control skills test, and the road test.
If you have studied a CDL manual in any other state, you already know this material. The CDL handbook Texas publishes covers the same federal regulations in these sections. The difference starts on the next page.
Section 14: The Texas Special Requirements
Section 14 contains Special Requirements for Texas Commercial Motor Vehicles and supports the Texas Commercial Rules subject that DPS lists first in its knowledge-test order. Use this manual page to locate the section. Use the separate Texas Commercial Rules study page for detailed explanations and practice.
The current handbook states an 80% standard for each knowledge test. DPS does not publish a guaranteed question count for this subject, so study the whole assigned section.
Vehicle Height, Width, and Length Limits
Texas has state-specific dimension rules. Read the conditions in Section 14 rather than treating one number as a guaranteed exam question.
- Maximum vehicle height in Texas: 14 feet. The federal standard used in most states is 13 feet 6 inches. If a test question asks about height in Texas, the answer is always 14 feet.
- Maximum width: 102 inches (8.5 feet). This matches the federal standard.
- Maximum length for a single motor vehicle: 45 feet.
- Maximum semi-trailer length: 59 feet.
- Maximum length for each trailer in a double-trailer combination: 28.5 feet.
The height trap: you will see questions that try to bait you with “13 feet 6 inches” as an answer choice because that is the standard everywhere else. Do not fall for it. In Texas, it is 14 feet.
Lighting, Reflectors, and Clearance Lamps
Section 14 goes deep into vehicle lighting requirements. You need to know the colors and mounting heights for specific lamps.
Clearance lamps: Every truck or bus 80 inches or wider must have:
- Front clearance lamps: Two, amber.
- Rear clearance lamps: Two, red.
Side marker lamps:
- Front side markers: Amber.
- Rear side markers: Red.
Reflectors: Every commercial motor vehicle must have at least two red reflectors mounted on the rear. The mounting height must be between 24 inches and 60 inches above the ground.
The farm tractor rule: Farm tractors and self-propelled farm equipment operating after dark must have two headlamps, one taillight, and two red reflectors. This sounds like a minor detail but it shows up on the exam frequently because Texas has a massive agricultural industry and the DPS wants drivers to know the minimum lighting for farm equipment sharing public roads.
Mud Flaps (Safety Guards)
This is an important equipment topic, but DPS does not publish a list of guaranteed questions.
All trucks and trailers with four or more tires on the rear axle must have safety guards (mud flaps) behind the rear wheels. The flaps must be suspended within 8 inches of the roadway surface.
The exam will offer choices like 6 inches, 8 inches, and 12 inches. The answer is 8 inches. Write it on your hand if you have to.
Cargo Extensions: Front and Rear Overhang
Texas law limits how far cargo can stick out past the body of the vehicle.
- Front overhang: No more than 3 feet beyond the front of the vehicle.
- Rear overhang: No more than 4 feet beyond the rear.
- If cargo extends more than 4 feet past the rear: You must attach a red flag at least 12 inches square during daylight hours, or a red light visible from 500 feet at night.
The connection between two towed vehicles (drawbar, chain, or cable) cannot exceed 15 feet. If you use a chain or cable, you must attach a white flag at least 12 inches square to the connection so other drivers can see it.
Coasting Is Illegal
This one catches experienced drivers off guard because it feels like common sense rather than law. In Texas, it is illegal to coast downhill with the transmission in neutral or the clutch disengaged.
The reason is straightforward: coasting kills your ability to accelerate out of danger and puts the full braking load on your service brakes. On a long Texas grade — think the hills outside Austin or the passes in West Texas — that means brake fade and potentially a runaway truck.
Railroad Crossing Rules
Section 14 reinforces the railroad crossing requirements with Texas-specific language:
- Vehicles carrying placarded hazardous materials must stop between 15 and 50 feet of the nearest rail.
- School buses and passenger buses must stop at all railroad crossings regardless of whether a train is visible.
- You must not shift gears while crossing the tracks. Select a gear before the crossing that will carry you all the way across.
Farm and Ranch Exemptions
Texas has enormous agricultural operations, and Section 14 carves out specific CDL exemptions for farmers that do not exist in federal law.
A farmer can operate a combination of vehicles that would normally require a Class A CDL without a CDL if all of the following conditions are met:
- The vehicle is controlled and operated by the farmer, a family member, or an employee of the farmer.
- The vehicle is used to transport agricultural products, farm machinery, or farm supplies to or from the farm.
- The vehicle is not used for hire (no common or contract carrier work).
- The vehicle is operated within 150 miles of the farm.
There is also a special provision for cotton vehicles. Vehicles transporting seed cotton modules can be up to 10 feet wide instead of the standard 102 inches, provided they are properly registered. This exemption exists because cotton module hauling is a seasonal, short-distance operation unique to Texas agriculture.
How to Use the Texas CDL Handbook to Study
Having the CDL handbook Texas provides is only useful if you know how to attack it. Here is the strategy that works.
Step 1: Download the Official PDF
The Texas DPS publishes the full Texas Commercial Driver License Handbook as a free PDF on the DPS website. You can also pick up a printed copy at any Texas driver license office. Do not pay anyone for a copy.
The handbook is roughly 180 pages. You do not need to read all of it cover to cover. Focus on the sections that match your testing requirements.
Step 2: Know Which Tests You Need to Pass
The Texas CDL permit test is not a single exam. It is a series of written knowledge tests. The ones you must take depend on the class of CDL and the endorsements you want.
For a typical Class A path, study the following subjects as they apply to the vehicle and transaction:
- Texas Commercial Rules — Texas-specific material, including Section 14.
- General Knowledge — core safe-driving, inspection and cargo concepts.
- Combination Vehicles — required for a Class A combination.
- Air Brakes — required when applicable to the vehicle and desired restrictions.
If you are adding endorsements, each one is a separate test:
- Tanker (N): study the Tank Vehicles section.
- HazMat (H): study Hazardous Materials and complete the separate ELDT and security steps.
- Passenger (P): study the Passenger Vehicles section.
- Doubles/Triples (T): study the Doubles and Triples section.
Step 3: Read Section 14 Twice
Read Section 14 once for structure, then a second time to connect each measurement to the vehicle, equipment or exception it governs.
Do not memorize a number without its conditions; that is how similar-looking rules get confused.
Step 4: Take Practice Tests
Reading alone is not enough. You need to test yourself under realistic conditions. After you finish studying Section 14, use a Texas CDL practice test that specifically covers the Special Requirements material. Most generic CDL practice apps do not include Section 14 questions because it is Texas-only content.
If you are also prepping for the General Knowledge exam, try our CDL General Knowledge Practice Test to gauge your readiness on the federal material.
Common Mistakes on the Texas CDL Permit Test
After watching thousands of drivers go through the Texas DPS testing process, these are the patterns that cause failures.
Mixing Federal and Texas Standards
The most dangerous mistake is confusing federal limits with Texas limits. The federal maximum vehicle height is 13 feet 6 inches. The Texas maximum is 14 feet. If a question says “in Texas,” answer with the Texas number. If it says “on the federal interstate system,” use the federal number.
Skipping Section 14 Entirely
This happens most often with experienced drivers who are transferring an out-of-state CDL to Texas. They assume the Special Requirements test is just a rehash of the General Knowledge exam. It is not. Section 14 covers material that does not exist in any other state’s manual. If you do not study it, you will fail it.
Relying on Generic CDL Apps
Most CDL practice test apps on the App Store are built around the federal model handbook. They do not include Texas-specific questions from Section 14. If you have been scoring 95% on a generic app and then fail the Special Requirements test at the DPS, this is why. Use a Texas Special Requirements practice test that pulls directly from the Texas Transportation Code.
Memorizing Wrong Numbers
The Section 14 exam is a numbers game. Here is a quick reference for the most-tested values:
| Measurement | Texas Value |
|---|---|
| Maximum vehicle height | 14 feet |
| Maximum vehicle width | 102 inches |
| Mud flap clearance | Within 8 inches of the road |
| Reflector mounting height | 24 to 60 inches above ground |
| Maximum front cargo overhang | 3 feet |
| Maximum rear cargo overhang (before flag required) | 4 feet |
| Maximum tow connection length | 15 feet |
| Farm exemption radius | 150 miles from the farm |
| Cotton module vehicle width | 10 feet |
| HazMat railroad crossing stop distance | 15 to 50 feet from nearest rail |
Use this table as an index, then verify each condition in the current handbook. DPS does not disclose that these values make up a fixed share of the live test.
The Texas CDL Permit Test: What to Expect at the DPS
When you arrive at the Texas DPS to take your written tests, here is what happens.
You check in at the counter and tell the clerk which tests you need. For a Class A CDL permit, you request General Knowledge, Combination Vehicles, Air Brakes, and Texas Special Requirements.
The clerk directs you to a computer testing kiosk. You take all four tests in one session. There is no time limit at most locations. You can skip questions and come back to them.
You must pass the knowledge tests assigned to your class, brake system and endorsements. Appointment and retest handling can vary, so confirm the next available attempt with DPS rather than relying on an old next-business-day promise.
What to bring:
- Proof of identity: Texas driver license or valid out-of-state license, plus a birth certificate or passport.
- Proof of residency: Two documents showing a Texas address (utility bill, bank statement, lease agreement).
- Social Security card or a document showing your SSN.
- DOT Medical Card: A valid Medical Examiner’s Certificate (Form MCSA-5876). Without this, the DPS will not issue your CLP.
- Payment: The CDL application fee in Texas is currently $97 for a new Class A CDL (valid for 8 years). Some locations accept credit cards, others only take checks or money orders. Check ahead.
If you are under 21, you will receive an intrastate-only restriction. You can only drive commercial vehicles within Texas until you turn 21.
Section 14 Compared to the Federal Manual
If you have already studied the federal CDL manual, here is a quick comparison showing where Texas goes its own way. This is not an exhaustive list, but it covers the areas that generate the most exam questions.
Vehicle height: Federal says 13 feet 6 inches on the National Network. Texas says 14 feet on state roads. The Texas CDL manual treats 14 feet as the standard answer.
Mud flaps: The federal regulations mention splash and spray suppression but do not give a specific measurement. Texas requires mud flaps within 8 inches of the ground for vehicles with four or more rear tires.
Farm exemptions: Federal law has a farm exemption (49 CFR 390.5), but Texas expands it with the 150-mile radius rule and the cotton module width exception. These are Texas Transportation Code provisions not found in the FMCSA regulations.
Coasting: Not specifically addressed in the federal commercial driver handbook. Texas makes it a clear violation under state law.
Cargo extension flags: The federal rules cover load securement but leave flag requirements more general. Texas specifies the 4-foot rear overhang threshold and the 12-inch square red flag or red light.
Frequently Asked Questions (FAQ)
What is Section 14 in the Texas CDL manual?
Section 14 covers the Special Requirements for Texas Commercial Motor Vehicles, including vehicle dimensions, lighting and reflector requirements, safety guards, cargo extensions, railroad crossings, operating rules and conditional exemptions. Follow the test list DPS assigns for your transaction.
How many tests do you take for a Texas CDL permit?
Texas DPS lists the order as Texas Commercial Rules, General Knowledge, Combination Vehicles, Air Brakes, then endorsements, with the latter subjects included when applicable to the requested class, vehicle and privileges.
Can I get the Texas CDL handbook for free?
Yes. The Texas DPS offers the complete Texas Commercial Driver License Handbook as a free PDF download on the DPS website. You can also pick up a free printed copy at most Texas driver license offices. Do not pay any third-party website for a copy of the handbook.
Conclusion: Do Not Skip Section 14
The Texas CDL manual combines the core commercial-driving curriculum with Texas-specific material. Use the section map above to study only what applies to your transaction.
Start by downloading the free CDL handbook Texas provides from the DPS website. Then continue to the page that matches your intent: Texas CDL requirements, General Knowledge, Texas Commercial Rules, or Texas HazMat.