Traffic Control and DUI Flashcards

What is the per se blood alcohol concentration (BAC) limit for non-commercial drivers age 21 and over in all U.S. states?

Answer: 0.08%

A BAC of 0.08% is the legal per se limit for adult non-commercial drivers in every U.S. state.

Which test is most commonly used as a Standardized Field Sobriety Test (SFST) and measures involuntary eye jerking?

Answer: Horizontal Gaze Nystagmus

Horizontal Gaze Nystagmus measures the involuntary jerking of the eyes that becomes pronounced under alcohol impairment.

Under implied consent laws, what is the typical consequence of refusing a chemical test after a lawful DUI arrest?

Answer: Administrative license suspension

Implied consent laws impose an automatic administrative license suspension for refusing a chemical test.

When directing traffic at an intersection, what does an officer's raised palm facing a driver mean?

Answer: Stop

A raised open palm facing the driver is the universal signal to stop.

What is the lower 'zero tolerance' BAC limit commonly applied to drivers under age 21?

Answer: 0.00% to 0.02%

Zero tolerance laws set the limit for underage drivers at 0.00% to 0.02% depending on the state.

During a DUI stop, which observation would NOT typically establish reasonable suspicion before the stop?

Answer: Driving with a passenger asleep

A sleeping passenger is not evidence of impaired driving, unlike erratic vehicle movements.

What is the legal BAC limit for commercial drivers operating a commercial vehicle in the U.S.?

Answer: 0.04%

Commercial drivers are held to a stricter 0.04% BAC limit while operating commercial vehicles.