Law Enforcement Traffic Control and DUI Questions and Answers 1 — Questions and Answers
Question 1: An officer is manually directing traffic at an intersection where the traffic signals are functioning normally. The signal facing an approaching driver is green, but the officer is giving a clear hand signal to stop. What is the driver's legal obligation?
- Proceed cautiously as the traffic light is green.
- Obey the officer's command and come to a complete stop. (Correct answer)
- Honk to acknowledge the officer and then obey the traffic signal.
- Wait for the officer's signal and the traffic light to match.
Correct answer: Obey the officer's command and come to a complete stop.
The commands of a law enforcement officer directing traffic always supersede any traffic control devices, including signals, signs, or pavement markings. This is a fundamental rule of traffic control to ensure safety and order at incident scenes or during periods of heavy congestion.
Question 2: Which of the following best describes the principle of 'Implied Consent' laws in the context of a DUI investigation?
- Drivers implicitly agree to a vehicle search if they are stopped for a traffic violation.
- An officer must obtain explicit verbal consent before administering any field sobriety tests.
- By operating a motor vehicle, a driver is deemed to have consented to a chemical test for intoxication if lawfully arrested for DUI. (Correct answer)
- A driver's consent to an evidentiary breath test is only implied if they have a prior DUI conviction.
Correct answer: By operating a motor vehicle, a driver is deemed to have consented to a chemical test for intoxication if lawfully arrested for DUI.
Implied Consent laws stipulate that any person who operates a motor vehicle on public roads has, by that action, consented to a chemical test (breath, blood, or urine) to determine their blood alcohol concentration if they are lawfully arrested for driving under the influence. Refusal to submit to this post-arrest test typically results in administrative penalties, such as license suspension.
Question 3: An officer, investigating a suspected DUI driver, asks the driver to stand with their feet together, keep their arms at their sides, raise one leg approximately six inches off the ground, and hold that position for 30 seconds while counting aloud. This procedure is known as which Standardized Field Sobriety Test (SFST)?
- Horizontal Gaze Nystagmus
- Walk-and-Turn
- Romberg Test
- One-Leg Stand (Correct answer)
Correct answer: One-Leg Stand
The One-Leg Stand is one of the three tests that comprise the NHTSA-validated Standardized Field Sobriety Tests (SFSTs). It is a divided attention test that assesses an individual's ability to balance and count simultaneously, tasks that can be difficult for an impaired person.
Question 4: During the 'Vehicle in Motion' phase of a DUI investigation, an officer observes a car straddling the lane line and then making an unusually wide turn. These observations are most critical for establishing what legal standard?
- Proof beyond a reasonable doubt for a conviction.
- Probable cause for an immediate arrest.
- Reasonable suspicion to initiate a traffic stop. (Correct answer)
- The driver's exact blood alcohol concentration.
Correct answer: Reasonable suspicion to initiate a traffic stop.
Observations of driving behavior, such as straddling lane lines or making wide turns, are known as DUI detection cues. These cues provide an officer with the reasonable suspicion required by law to initiate a traffic stop and investigate further. They do not, by themselves, constitute the higher standard of probable cause for arrest.
Question 5: What is the primary purpose of a Preliminary Alcohol Screening (PAS) device used by an officer during a roadside DUI stop?
- To provide the definitive and admissible BAC evidence for use in court.
- To help establish probable cause to make a DUI arrest. (Correct answer)
- To medically diagnose the driver's level of intoxication for treatment.
- To satisfy the final requirement of the Implied Consent law.
Correct answer: To help establish probable cause to make a DUI arrest.
A PAS device is a portable breathalyzer used as a field sobriety test to help an officer determine if there is probable cause to arrest a driver for DUI. The results from these handheld devices are generally not admissible in court to prove a specific BAC level; an evidentiary-grade chemical test is required for that purpose after an arrest has been made.
Question 6: In all 50 U.S. states, it is illegal 'per se' for a non-commercial driver, age 21 or older, to operate a motor vehicle with a Blood Alcohol Concentration (BAC) at or above which specific level?
- 0.10%
- 0.05%
- 0.08% (Correct answer)
- 0.02%
Correct answer: 0.08%
A BAC of 0.08% is the 'per se' illegal limit for drivers aged 21 and over in all 50 states (with Utah also having a lower 0.05% limit). 'Per se' means that having a BAC at or above this level is, in and of itself, a crime, regardless of whether the driver exhibits visible signs of impairment.
Law Enforcement Traffic Control and DUI Questions and Answers 1
An officer is manually directing traffic at an intersection where the traffic signals are functioning normally.
The signal facing an approaching driver is green, but the officer is giving a clear hand signal to stop.
What is the driver's legal obligation?