For operations covered by 49 CFR 392.5, how long before going on duty must a driver avoid alcohol?
Correct answer: At least four hours
Four hours is the minimum interval. Remaining alcohol or impairment still prohibits duty.
Source: 49 CFR 392.5(a)(1) ↗
A driver covered by 49 CFR 392.5 has a measured alcohol concentration below 0.04. Does that alone make on-duty driving permissible?
Correct answer: No; the rule prohibits any measured alcohol concentration on duty
The on-duty prohibition is separate from the 0.04 disqualification threshold.
Source: 49 CFR 392.5(a)(2) ↗
A driver receives an out-of-service order for violating 49 CFR 392.5. What period does this alcohol rule specify?
Correct answer: 24 hours from issuance of the order
The order starts the 24-hour period, and its terms must be obeyed.
Source: 49 CFR 392.5(c) ↗
Which alcohol concentration does Texas DPS identify as a commercial-driving disqualification ground while operating a CMV?
Correct answer: 0.04 or greater
This CMV threshold is not permission to drive with a lower concentration or while impaired.
Source: CDL Disqualification Reinstatement: alcohol concentration while operating a CMV ↗
After drinking, a driver uses strong coffee and a cold shower. What happens to the time needed for the body to eliminate alcohol?
Correct answer: Those measures do not speed alcohol elimination
Feeling more awake is not the same as being sober. The body needs time to process alcohol.
Source: Texas DL-7C March 2026, section 2.22.1: How Alcohol Works, PDF page 67 ↗
Why can a driver who has been drinking be a poor judge of their own fitness to drive?
Correct answer: Alcohol can impair judgment and self-control early
Early impairment can weaken the very judgment needed to recognize the danger.
Source: Texas DL-7C March 2026, section 2.22.1: Alcohol and the Brain, PDF page 68 ↗
Does choosing beer instead of spirits eliminate the risk of alcohol-related driving impairment?
Correct answer: No; beer, wine and spirits can all supply impairing alcohol
The alcohol dose matters. The type or reputation of the drink does not make driving safe.
Source: Texas DL-7C March 2026, section 2.22.1: What Is a Drink?, PDF page 68 ↗
You cannot remember the last few miles and have missed a familiar exit. What should these signs suggest?
Correct answer: Possible fatigue requiring a safe stop and rest
Memory gaps and missed signs are listed fatigue warnings, even without obvious head nodding.
Source: Texas DL-7C March 2026, section 2.11.2: Warning Signs of Fatigue, PDF page 53 ↗
You can choose between equally lawful trip schedules. Which better follows the handbook’s fatigue-prevention guidance?
Correct answer: Driving during hours when you are normally awake
Plan around normal waking hours and adequate rest. A convenient schedule does not remove the need for sleep.
Source: Texas DL-7C March 2026, section 2.11.2: Preventing drowsiness before a trip, PDF page 53 ↗
Why is repeated coffee an unreliable plan for completing a trip without adequate rest?
Correct answer: Its temporary alerting effect wears off and does not replace sleep
The handbook warns against relying on caffeine to prevent fatigue. Rest remains necessary.
Source: Texas DL-7C March 2026, section 2.11.2: Maintaining alertness while driving, PDF page 53 ↗
A cardboard box lies in your lane. Why should you avoid assuming it is safe to drive over?
Correct answer: It may hide heavy or solid contents that damage the vehicle
Recognize debris early and choose a safe response without a sudden uncontrolled maneuver.
Source: Texas DL-7C March 2026, section 2.8.2: Foreign Objects, PDF page 46 ↗
Your truck’s right wheels run near a sharp pavement drop-off beside a sign. What added clearance hazard can develop?
Correct answer: The vehicle can tilt and move its upper body toward the sign
An uneven edge can tilt a tall vehicle toward roadside objects and make steering difficult.
Source: Texas DL-7C March 2026, section 2.8.2: Drop Off, PDF page 46 ↗
You see the rear of a van projecting from an alley, but its driver is hidden from your view. What is the safer assumption?
Correct answer: The driver may not see you and could enter your path
Prepare for the vehicle to emerge. Seeing part of another vehicle does not establish that its driver sees you.
Source: Texas DL-7C March 2026, section 2.8.3: Blocked Vision, PDF page 47 ↗
A bicyclist ahead repeatedly looks over one shoulder without signaling. What possible action should you anticipate?
Correct answer: A lane change or turn
Head and body movements can warn of a maneuver before a turn signal or hand signal appears.
Source: Texas DL-7C March 2026, section 2.8.3: Driver Body Movement as a Clue, PDF page 48 ↗
You notice a possible hazard while there is still ample space ahead. What should accompany your observation?
Correct answer: Consider how it could develop and identify a safe response
Early recognition provides time to plan. Keep monitoring because the situation can change.
Source: Texas DL-7C March 2026, section 2.8.4: Always Have a Plan, PDF page 48 ↗
A car near a freeway exit suddenly slows while its driver appears undecided. What should you be ready for?
Correct answer: An unexpected return toward the through lanes
Hesitation near an exit can precede a sudden direction change. Preserve room and monitor a safe escape option.
Source: Texas DL-7C March 2026, section 2.8.1: Importance of Seeing Hazards, PDF page 46 ↗
You approach a stopped car with a raised hood and a wheel on a jack. Which additional hazard should you anticipate?
Correct answer: A person working near the traffic lane who may not notice you
Repair activity can draw a person’s attention away from passing traffic. Recognize the hazard early and proceed safely.
Source: Texas DL-7C March 2026, section 2.8.3: Disabled Vehicles, PDF page 47 ↗
Your truck begins hydroplaning through standing water. What should you do with the accelerator and brakes?
Correct answer: Ease off the accelerator and avoid braking while traction returns
The tires have lost road contact. Let the vehicle slow; on a manual vehicle, the chapter also directs disengaging the clutch.
Source: Texas DL-7C March 2026, section 2.6.2: Hydroplaning, PDF page 42 ↗
The temperature is below freezing, but the road only appears wet. What hidden hazard should you consider?
Correct answer: A thin transparent layer of black ice
Clear ice can leave the pavement visible, creating a misleading wet appearance. Reduce speed for the conditions.
Source: Texas DL-7C March 2026, section 2.6.2: Black Ice, PDF page 42 ↗
Under otherwise comparable conditions, increasing speed from 20 to 40 mph makes the handbook’s braking distance about how much longer?
Correct answer: Four times as long
This relationship concerns braking distance. Perception and reaction distance are separate parts of total stopping distance.
Source: Texas DL-7C March 2026, section 2.6.1: The Effect of Speed on Stopping Distance, PDF page 41 ↗
