Field Sobriety Tests in Pennsylvania DUI Cases: What Drivers Need to Know

In Pennsylvania, when police officers conduct a DUI traffic stop, they often ask drivers to perform field sobriety tests (FSTs) to determine whether there is probable cause for a DUI arrest.  These tests are widely used in Wilkes-Barre, Kingston, Hazleton, Pittston, Nanticoke, and across Luzerne County, but they are far from perfect — and many sober drivers fail them.

Understanding what these tests are, why they're flawed, and what your rights are can make a major difference in a DUI case.

The Three Standardized Field Sobriety Tests

Police officers in Pennsylvania most commonly use three standardized field sobriety tests recognized by the National Highway Traffic Safety Administration (NHTSA):

1. Horizontal Gaze Nystagmus (HGN) Test

During this test, an officer tracks your eye movements with a stimulus such as a pen or flashlight. Involuntary jerking of the eyes, known as nystagmus, may be taken as a sign of impairment. However, medical conditions, fatigue, or even contact lenses can influence results.

2. Walk-and-Turn Test

The driver is instructed to walk heel-to-toe in a straight line, turn, and walk back. If you lose balance, take the wrong number of steps, or fail to follow directions exactly, the officer may claim this is evidence of intoxication.

3. One-Leg Stand Test

This requires standing on one leg for a set time while following instructions. Officers look for swaying, hopping, or putting your foot down early. Again, nerves, injuries, or uneven ground can unfairly impact performance.

Both the Walk-and-Turn and One-Leg Stand are divided attention tests, assessing coordination and ability to follow directions while performing physical tasks.

Problems With Field Sobriety Tests

While police present FST results as evidence of impairment, these tests are far from perfect. Common problems include:

• Subjective interpretation – Officers often decide a driver is impaired before tests even begin.
• Medical or physical conditions – Inner ear issues, back problems, or fatigue can mimic impairment.
• Environmental factors – Poor lighting, uneven pavement, or bad weather can cause mistakes.
• Nervousness – Simply being pulled over can make even sober drivers stumble or hesitate.

Because of these flaws, FST results are not foolproof and can often be challenged in court.

Can You Refuse Field Sobriety Tests in Pennsylvania?

Yes. Pennsylvania law does not require drivers to perform field sobriety tests. Unlike chemical testing (breath or blood tests), refusing FSTs does not carry automatic license suspension or legal penalties.

However, police may still consider your refusal when deciding whether probable cause exists for a DUI arrest. In Commonwealth v. Angel, 946 A.2d 115 (Pa. Super. 2008), the court confirmed that refusal may be a factor in determining probable cause.

Protect Your Rights After a DUI Arrest in Luzerne County

If you or a loved one were charged with DUI in Wilkes-Barre, Kingston, Plains Township, Hazleton, Pittston, Nanticoke, or anywhere in Northeastern Pennsylvania, it is critical to speak with an experienced DUI defense lawyer immediately. Field sobriety tests are not as reliable as police make them seem, and a skilled attorney can challenge their accuracy.

At Sklarosky Law, we have extensive experience exposing the weaknesses in FST results and fighting to protect your rights.

Call us today at (570) 283-1200 or use our online contact form to schedule a consultation.  We're ready to help you build the strongest defense possible.