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How accurate are roadside field sobriety tests?

On Behalf of | Oct 19, 2021 | Criminal Defense |

When you get pulled over and the officer thinks you may be impaired, he or she likely won’t give you a breath test right away. Portable breath tests are not the same as the ones at the station, which are used in court. Instead, the officer may just give you field sobriety tests and take you to the station to use a Breathalyzer if you fail those tests.

The three main tests used at this time are the horizontal gaze nystagmus test, the walk and turn test and the one-leg stand. You may hear of things like officers asking you to recite the alphabet or something of this nature, but they aren’t really used. These three tests are the standard. But do they work?

Tests show surprising failure rates

They don’t work 100% of the time, and it’s not even all that close. In one study, the absolute highest success rate found was about 82%. And that was only if the officer did all three tests. They would still get it wrong twice for every 10 people they tried it on, meaning they could make all sorts of arrests when people weren’t impaired.

With just one test being used, the results were notably worse. Some reports claimed they were as low as 47% in terms of overall success rate. The HGN test worked best, at 77%, but the one-leg stand was just 65% and the walk and turn was just 68%.

Now, the police may contest that these tests work the majority of the time, and that is statistically true. However, most people assume something like that means that it’s 95% effective. It doesn’t. It just means more than 50%. Are we really happy with a testing system if it gets it right only 6 out of 10 times? Think of the hundreds of arrests made every month and ask yourself how many people were not impaired at all when they failed those tests.

Are you facing charges?

Inaccurate testing can lead to an arrest on impaired driving allegations that never should have happened. If you find yourself facing charges, you need to understand all of the legal options you have.