What Happens During a DUI Traffic Stop?

During a DUI traffic stop, law enforcement will pull over a driver whom they believe may be driving under the influence. By stopping the vehicle, the police officer will further investigate the driver for signs of inebriation. A DUI traffic stop consists of the initial reason for the traffic stop, assessing the driver’s behavior, requesting that the driver perform field sobriety testing, administering a breathalyzer test, and arresting the driver if there are indications of intoxication. If you have questions regarding the legality of a recent DUI stop, our Nashville DUI lawyers are more than happy to speak with you.

Initial Traffic Stop

If you are braking erratically, unable to maintain lane position, or are in violation of a traffic law, law enforcement has reasonable suspicion to stop you. As soon as you see flashing lights in your rearview mirror or hear a siren, you should pull to the side of the road. At this point, the officer may suspect that you are driving under the influence but will need to investigate further.

Assessing Your Behavior

During the stop, the police officer may ask for your license, proof of registration, and insurance information. The officer may ask you to state your full name and address. The officer will gauge your ability to follow instructions as well as observe you. If you have bloodshot eyes, slurred speech, or are becoming agitated or confused, the officer may suspect that you are impaired.

Field Sobriety Testing

If your behavior raises any red flags, the officer will ask you to participate in field sobriety testing. Standard field sobriety testing (FST) consists of three tests: a horizontal gaze nystagmus (HGN), a walk-and-turn, and a one-leg stand. These tests all measure physical and cognitive abilities, while also highlighting impairments. Tennessee law does permit you to refuse FST without suffering any legal repercussions. However, the police officer is under no obligation to tell you that you are allowed to refuse testing.

Breathalyzer Test

Before a DUI arrest, the officer will typically conduct a preliminary breath test (PBT). The PBT is a handheld device that tests the presence of alcohol on your breath. You will breathe into the device, which will produce a BAC reading. Although you are allowed to refuse a PBT without suffering immediate legal consequences, our legal team recommends that you comply.

DUI Arrest

By being a licensed driver in the state of Tennessee, you must comply with all blood chemistry tests following a DUI arrest. If a breathalyzer test shows a BAC below 0.08%, the officer may take a blood sample (which is more accurate). As of January 1, 2026, Tennessee law allows oral fluid testing, which can be administered as part of roadside testing. The oral fluid mobile testing devices will detect the use of any of the six drug classes to see what substances are present in the driver’s system besides alcohol. The oral fluid testing is only administered once probable cause has been established to initiate a DUI arrest.

Combating DUI Charges

Given the uptick in DUI accidents in Nashville in recent years, law enforcement has been more aggressively pursuing inebriated drivers. A DUI arrest is based on evidence establishing probable cause, such as breaking traffic laws, slurred speech, bloodshot eyes, a positive breath test (0.08% BAC or greater), or failing one or more field sobriety tests. However, these criteria are not always reliable. For example, a breathalyzer could be poorly calibrated, showing a false reading, and any number of medical conditions could cause you to fail a field sobriety test. At Andrew C. Beasley, PLLC, we will question whether the facts point to impairment or if there are other factors involved that may have skewed your results.

Do Not Hesitate to Contact Our Nashville DUI Lawyers

A DUI conviction can result in serving time behind bars, losing your license, and paying steep fines. Once your sentence is served, you will likely have a difficult time finding work, housing, and even renewing professional licensure. The best way to avoid a conviction is to obtain representation immediately following arrest. At Andrew C. Beasley, PLLC, our legal team will assess your situation to determine the best approach for a successful case outcome. To arrange a free consultation with one of our Nashville DUI attorneys, we can be reached online or by calling (615) 846-9889 as soon as possible.