CDL Foundations

This module builds the commercial-driver mindset: space management, speed control, hazard awareness, and emergency judgment all carry more weight when the vehicle is bigger and slower to recover. Treat these topics as operating principles, because later air-brake, inspection, and combination-vehicle questions all assume you already think in terms of consequence and margin.

The rules that matter

1. Follow at one second per ten feet of vehicle length below 40 mph, and add one more second above 40 — a 40-foot rig at highway speed needs at least five.
2. Trucks swing wide to turn right because the trailer's rear wheels track inside the turn; the gap that opens on your right is exactly where the trailer is about to be.
3. An empty truck needs more room to stop, not less — the brakes and tires are built for a loaded weight that isn't there, so there's less traction.
4. When a vehicle comes at you head-on with no time to brake, leave the road to the right; running onto the shoulder beats a head-on almost every time.
5. Only rest fixes fatigue — coffee and fresh air just delay the crash, which is the whole reason hours-of-service limits exist.
6. Property-carrying drivers get 11 hours of driving after 10 hours off, inside a 14-hour window, capped at 60 hours in 7 days or 70 in 8.
7. Plan the run against the clock you have: 11 driving hours inside 14, a 30-minute break before 8 hours of driving, and 60 in 7 or 70 in 8 days.
8. Check cargo securement within the first 50 miles, then at every duty change, 3 hours or 150 miles — whichever comes first.
9. Hand-held phone use while driving is prohibited, and sitting at a red light still counts as driving.
10. Flashers go on the moment you stop on the road; the three warning devices are down within 10 minutes.
11. Coercion — a threat to your work to make you violate a rule — is illegal, and the complaint window is 90 days.
12. Fired for refusing to run unsafe or illegal? The whistleblower complaint goes to the Secretary of Labor within 180 days.
13. Reach the intersection before swinging wide on a right turn, and never cut a left turn short — the trailer tracks inside your line either way.
14. Pick the gear before the grade. Once the combination is rolling downhill, no lower gear will match the road speed and you are left with brakes alone.
15. Only sleep fixes fatigue, and hours-of-service limits are a ceiling rather than a target: stop when fatigue arrives, even with hours left.
16. After a crash, check yourself first, then flashers and warning devices, then the calls — the second crash into the first is what kills people.
17. No alcohol within four hours of safety-sensitive work, none during it, and none for eight hours after a crash that requires a test.
18. Interstate driving needs age 21, one state's commercial license, 20/40 vision in each eye, and a medical exam at least every 24 months.

Read this in the handbook

Look for these sections: General Knowledge, Safe Driving, Emergency, Hours of Service, Trip Planning, Communications on the Job, Driver Rights, Coercion and Whistleblower Protection, Basic Vehicle Control, Shifting and Transmissions, Fatigue and Wellness, After a Crash, Drug and Alcohol Rules, Medical Qualification.

This content comes from the federal FMCSA regulations (49 CFR), not a state handbook, so the rules are the same nationwide. Your state agency may add its own endorsement requirements on top.