Field sobriety tests are used to determine probable cause for a DWI arrest during a roadside stop, but they often show inaccurate results that get innocent drivers arrested.
Field Sobriety Tests are Risky
When a police officer pulls a driver over for suspicion of drunk driving, the driver will likely be subjected to one or more field sobriety tests to gauge the level of impairment. These tests use a variety of measures to help police officers determine a driver’s physical and cognitive abilities. A driver may be asked to perform certain tasks such as:
- Walking a straight line
- Standing on one leg
- Touching the nose with the index finger
- Counting the number of fingers raised by the officer
- Taking a horizontal gaze nystagmus test
- Taking a preliminary breath test (PBT)
Although these tests are usually difficult for most drunk drivers, many sober drivers can’t perform the required tasks. Sobriety field tests do not accurately gauge a person’s level of impairment well enough to warrant probable cause for arrest.
Under Minnesota law, drivers are not legally obligated to take field sobriety tests. Most drivers comply because they don’t know the law or they’re trying to avoid a DWI arrest and conviction. Many people think they’re required to take a preliminary breath test (PBT) when they are pulled over. However, a PBT is performed on the scene using a hand-held device and is not required by law. In some cases, drivers who have been drinking take the PBT test out of fear of getting arrested, even if their alcohol levels are below the legal limit of .08. Drivers are only required to submit to chemical tests that measure BAC through a breathalyzer, blood, or urine test. These are normally performed at a hospital, police station, or jail.
Field sobriety tests, standardized by the National Highway Traffic Safety Administration, have been used by police officers for several decades. Studies show that the horizontal gaze nystagmus test used to track involuntary eye movement can register a false level of alcohol because of 40 different medical conditions, other than intoxication. Since field sobriety tests often have inaccurate results that may show probable cause for a DWI arrest, drivers should know they have a legal right to refuse the tests. A Minneapolis drunk driving lawyer often advises drivers to politely refuse field sobriety tests.