Guide · Updated Oct 7, 2026
Texas CDL Section 14: What the Handbook Says
Section 14 is the chapter of the Texas Commercial Motor Vehicle Driver's Handbook titled "Special Requirements for Texas Commercial Motor Vehicles." The handbook tells you to pay close attention to it before the knowledge exams.
What the handbook says about the exams
The Texas Department of Public Safety (DPS) handbook, form DL-7C, says the knowledge exams are multiple choice and matching. It lists them in the order they are given:
- Texas Commercial Rules
- General Knowledge
- Combination (if required)
- Airbrakes (if required)
- Double/Triple Trailer (if required)
- Passenger (if required)
- School Bus (if required)
- Tanker (if required)
- HazMat (if required)
It also says a score of 80% or higher is required to pass each section. It does not give a question count.
The handbook does not say in words that Section 14 is the Texas Commercial Rules exam. It does not say in words who must take that exam. Ask DPS if you are not sure which exams you need. The last page of Section 14 lists five questions and says, "These questions may be on your test." So learn the whole chapter.
DPS also announced that all Texas CDL and CLP knowledge exams are English only for applicants scheduled on or after June 1, 2026. Interpreters are prohibited. DPS says the handbook and study materials are free on its website.
The Section 14 numbers
These come from the handbook.
| Rule | The number |
|---|---|
| Greatest height, including load | 14 feet |
| Greatest width, including load | 102 inches |
| Single motor vehicle other than a truck tractor, length | 45 feet |
| Semitrailer in a truck tractor and semitrailer combination | 59 feet |
| Semitrailer or trailer in a truck tractor, semitrailer and trailer combination | 28-1/2 feet each |
| Combination other than a truck tractor-trailer combination | 65 feet |
| Vehicles in a combination | Not more than three |
| Greatest weight, vehicle or combination with load | 80,000 pounds |
| Weight tolerance before you may be made to unload | 5% |
| Load past the front | No more than 3 feet |
| Load past the rear | No more than 4 feet. Past that, a red flag at least 12 inches square by day and a red light visible for 500 feet at night |
| Tow connection | Not longer than 15 feet. A chain, rope or cable needs a white flag at least 12 inches square |
| Mud flaps | Trucks and trailers with four or more tires on the rear axle. Flaps reach within 8 inches of the road |
| Warning devices | At least three flares, three red electric lanterns or three portable red emergency reflectors |
| Hazard lights | When a truck, bus, tractor or trailer 80 inches or more wide, or 30 feet or more long, stops on a roadway or shoulder |
| Reflector height | 24 to 60 inches above the ground on vehicles 80 or more inches wide |
The handbook says vehicles may legally exceed 80,000 pounds under certain conditions with an oversize/overweight permit. For a load heavier, longer, wider or higher than the law allows, you must get a special permit.
The handbook lists exceptions to these size rules, such as farm, cotton and timber cases. It also says the length rules do not apply within city limits.
Operating rules in Section 14
- Coasting. It is unlawful for a commercial motor vehicle to coast down any grade, even with the clutch disengaged and the transmission in gear. Shift to a lower gear before you start down.
- Railroad crossings. If you drive a bus, a school bus or a vehicle displaying placards, you must stop at all railroad grade crossings unless a signal or officer says to go. Trucks carrying explosives must also stop.
- Two-wheeled vehicles. Leave at least six feet to the left. Do not share the lane. Move into the next or oncoming lane.
- Following distance. The handbook says to keep four seconds on the open road and 6 to 8 seconds in bad weather.
- Disabled vehicle. The first thing the driver must do is put out the proper flares, flags or reflectors.
How to study Section 14
- Read the chapter once, start to finish, in the free DPS handbook.
- Write the numbers table from memory. Do it again the next day.
- Answer the five "Test Your Knowledge" questions at the end without looking.
- Learn the exceptions last. They are easy to mix up with the main rules.
The General Knowledge exam covers the rest of the handbook. Our General Knowledge test guide shows how to study it. The Texas CDL practice test page has the Texas facts we checked.
Try 10 exam-style questions built from the official CDL manual.
FirstTry CDL is not affiliated with any DMV, FMCSA or government agency. Practice questions are exam-style questions built from the official CDL manual, not actual test questions.
Common questions
Is Section 14 the Texas Commercial Rules exam?
The handbook does not say so in words. It lists Texas Commercial Rules first in the order of knowledge exams. It also tells you to pay close attention to Section 14. Study all of Section 14 and read the handbook's exam list for yourself.
How many questions are on the Texas test and what is the passing score?
The handbook says a score of 80% or higher is required to pass each section. It does not give a question count.
Can I take the Texas CDL knowledge tests in Spanish?
No. Texas DPS says that for applicants scheduled on or after June 1, 2026, all CDL and CLP knowledge exams are given in English only, and interpreters are prohibited.
Sources
- Texas Commercial Motor Vehicle Driver's Handbook (DPS form DL-7C, revised March 2026)
- Texas DPS: DPS Announces Changes to CDL Knowledge Testing
Rules and numbers can differ by state. See how we source facts.