Robert F. Rider, PLC
One Of Roanoke’s Most Experienced Defense Attorneys.
Get Legal Help Now! 540-685-0075

Are field sobriety tests accurate and reliable?

You haven’t been drinking, but you know why the officer thinks so when the lights come on. You accidentally swerved over the center line while trying to change the radio station. No other cars are in view, behind or in front of you, so an accident wasn’t a real threat. However, you know that’s likely to trigger a traffic stop at midnight because it looks like you’re drunk.


Sure enough, the officer asks you if you’ve been drinking, and you answer honestly. But then the officer asks you to get out of the car and do some field sobriety tests. You can’t believe it, but you go along with it because you know it’s best to follow directions from the police. You don’t want any trouble.

It’s dark, so you get a bit confused during the test where you’re supposed to walk a straight line, turn around and come back. The ground is wet from the rain earlier in the day, and you slip and almost fall as you turn around. You want to laugh it off, but you see the way the officer is looking at you.

When you get back, the officer arrests you and says it’s clear that you’re intoxicated. Nothing you can say helps. You protest your innocence, but you’re arrested anyway.

This can happen

Many people trust field sobriety tests, assuming they accurately sort drunk drivers from sober drivers, which is why it’s important to note that this type of arrest can happen. Many researchers don’t think field tests are accurate or reliable. That doesn’t mean they’re always wrong, but does it mean officers should trust them when establishing guilt? How many DUI arrests get made in error?

Test results

To test the tests, if you will, the Southern California Research Institute (SCRI) and the National Highway Traffic Safety Administration (NHTSA) brought in numerous people and had them carry out tests for officers to watch. Some were intoxicated and some were not.

The error rate as officers tried to sort them was a stunning 47 percent. That’s nearly half of the cases. Some tests were more useful than others, but even the common walk and turn test — the one you failed on that dark night on the side of the road — was only accurate 68 percent of the time. That means that almost one out of every three arrests could get made in error.

Other tests were even worse. Having people stand on one leg, for instance, was only right 65 percent of the time.

Accuracy in question

With results like that, it’s natural to question the accuracy of the tests. Those who have failed them must know all of their options moving forward.