What minimum tread depth is required in the major grooves of the front tires on a commercial truck?
Correct answer: 4/32 inch
Front tires on buses, trucks and truck tractors need at least 4/32 inch in major grooves; the general minimum for other tires is 2/32 inch. Do not measure on tie bars, humps or fillets.
Source: Florida Commercial Driver's License Manual (July 2022), section 2.1.3, printed p. 2-1, physical PDF page 27: Tire problems ↗
During the CDL vehicle inspection test, what must an applicant do when identifying an item?
Correct answer: Point to or touch it, name it, and explain what you would inspect and why
Identify the component and explain the condition you would check and its safety purpose. Follow the instructions for the test format being administered.
Source: Florida Commercial Driver's License Manual (July 2022), section 2.1.4, printed p. 2-3, physical PDF page 29: CDL vehicle inspection test ↗
What extra following time should be added when traveling above 40 mph?
Correct answer: One additional second
Apply the length rule, then add one second when speed exceeds 40 mph.
Source: Florida Commercial Driver's License Manual (July 2022), section 2.7.1, printed p. 2-16, physical PDF page 42: Space ahead ↗
Under the federal cargo-inspection rule, when must the driver first recheck securement on an accessible, unsealed truck load after starting the trip?
Correct answer: Within the first 50 miles
Inspect within the first 50 miles and correct any insecure loading. Separate exceptions apply to sealed loads the driver is ordered not to open and loads that cannot practicably be inspected.
Source: 49 CFR 392.9(b)(2), (4): initial cargo recheck and sealed/inaccessible-load exceptions; related Florida handbook (July 2022), section 3.1; 2.1.6, printed 3-1, 2-7, PDF 71, 33 ↗
Under the federal rule for cargo tiedowns, what aggregate working load limit must they provide?
Correct answer: At least half the secured cargo's weight
The counted aggregate must be at least half the secured cargo's weight. Whether a tiedown ends at the cargo, returns to the same vehicle side or spans opposite sides affects how its rating counts; use the regulatory formula.
Source: 49 CFR 393.106(d)(1)–(3): tiedown aggregate working load limit and counted contributions; related Florida handbook (July 2022), section 3.3.2, printed 3-2, PDF 72 ↗
Before backing with a helper, which signal should you both agree on?
Correct answer: A clear stop signal
Keep the helper visible and agree on understood hand signals before backing. A clear stop signal is especially important.
Source: Florida Commercial Driver's License Manual (July 2022), section 2.2.4, printed p. 2-8, physical PDF page 34: Backing safely — helper signals ↗
You are looking 12 to 15 seconds ahead as recommended for commercial driving. How should you also monitor the nearer road?
Correct answer: Shift attention between distant and nearby conditions
Looking well ahead does not replace monitoring nearby hazards. The handbook describes shifting attention back and forth between near and far to maintain awareness.
Source: Florida Commercial Driver's License Manual (July 2022), section 2.4.1, printed p. 2-10, physical PDF page 36: Seeing ahead ↗
On a straight divided highway with a clear view, what spacing does the handbook give for the three warning devices behind a stopped truck?
Correct answer: 10, 100, and 200 feet toward approaching traffic
All three warn traffic approaching from the direction serving that roadway. Adjust for an obstructed view.
Source: Florida Commercial Driver's License Manual (July 2022), section 2.5.2; Figure 2.8, printed p. 2-12, physical PDF page 38: Warning devices on one-way or divided highways ↗
A car ahead drifts within its lane while its driver looks down repeatedly. How should you react?
Correct answer: Leave extra room and anticipate an unexpected movement
Recognizing distraction in another driver helps you protect your own space.
Source: Florida Commercial Driver's License Manual (July 2022), section 2.9.7, printed p. 2-23, physical PDF page 49: Watch for other distracted drivers ↗
A properly inflated tire’s pressure rises during hot-weather operation. Should you bleed air to its cold-pressure reading?
Correct answer: No, it could become underinflated when it cools
Heat raises pressure; follow cold-inflation specifications rather than vent hot tires.
Source: Florida Commercial Driver's License Manual (July 2022), section 2.14.1, printed p. 2-29, physical PDF page 55: Hot-weather tire checks ↗
One train has passed a crossing with two tracks. What must you check before proceeding?
Correct answer: Whether another train is approaching on either track
A train can conceal another train. Obey warning devices and verify the crossing is clear.
Source: Florida Commercial Driver's License Manual (July 2022), section 2.15.3, printed p. 2-31, physical PDF page 57: Multiple-track crossings ↗
After a collision, you are uninjured and able to act. What is an immediate priority?
Correct answer: Prevent another collision at the scene
Protect the area, request assistance, and keep emergency access clear.
Source: Florida Commercial Driver's License Manual (July 2022), section 2.20.1–2.20.2, printed p. 2-38, physical PDF page 64: Protect the crash area and notify authorities ↗
For a small fire you are trained to tackle safely, with the correct extinguisher and a clear escape path, where should you aim?
Correct answer: At the base of the fire
The extinguishing agent must reach the burning material rather than only the rising flames.
Source: Florida Commercial Driver's License Manual (July 2022), section 2.21.3, printed p. 2-39, physical PDF page 65: Using an extinguisher ↗
Why inspect a front-end header board before carrying a load?
Correct answer: It helps restrain forward cargo movement toward the cab
A sound front-end structure protects against cargo moving forward in a sudden stop.
Source: Florida Commercial Driver's License Manual (July 2022), section 3.3.3, printed p. 3-3, physical PDF page 73: Header boards ↗
Before moving an oversize or overweight load, what arrangements should you establish?
Correct answer: Permits, routing limits, and required warnings or escorts
A sign alone does not authorize a special load. Determine the applicable movement conditions and equipment before departure.
Source: Florida Commercial Driver's License Manual (July 2022), section 3.4.4, printed p. 3-3, physical PDF page 73: Oversized loads ↗
An approaching driver leaves bright lights on. What should you do?
Correct answer: Look toward the right edge reference without staring into the glare
Avoid adding glare or losing sight of your own lane; reduce speed when needed.
Source: Florida Commercial Driver's License Manual (July 2022), section 2.11.5, printed p. 2-27, physical PDF page 53: Avoiding oncoming glare ↗
When should you learn how to fit the chains carried for your drive tires?
Correct answer: Before encountering conditions that require them
Check fit and condition in advance so the equipment can be used correctly when required.
Source: Florida Commercial Driver's License Manual (July 2022), section 2.13.1, printed p. 2-28, physical PDF page 54: Tire chains ↗
Does buying a cold medicine without a prescription prove it is safe before commercial driving?
Correct answer: No, it may cause drowsiness or impair driving
Check warnings and appropriate medical advice; over-the-counter availability is not a safety guarantee.
Source: Florida Commercial Driver's License Manual (July 2022), section 2.22.2, printed pp. 2-41, 2-42, physical PDF pages 67, 68: Other drugs and warning labels ↗
A breakdown forces your truck to stop on the highway shoulder. Which lights should you switch on immediately to warn approaching traffic?
Correct answer: The four-way emergency flashers
Flashers warn that the vehicle is stopped. They do not replace the required warning devices that must also be placed promptly.
Source: Florida Commercial Driver's License Manual (July 2022), section 2.5.2, printed p. 2-12, physical PDF page 38: Roadside warning flashers ↗
A newer streamlined truck climbed a hill in a relatively high gear. Should you automatically use that same gear to descend?
Correct answer: No, the descent may require a lower gear suited to that truck and grade
Reduced drag and different engine performance can make the old same-gear rule unsuitable. Select the correct low gear before descending.
Source: Florida Commercial Driver's License Manual (July 2022), section 2.16.2, printed p. 2-32, physical PDF page 58: Gear selection for modern trucks ↗
