For many years now, California law enforcement officers have administered specific tests before they arrest a driver and charge them with suspected driving under the influence of alcohol. These tests, commonly called field sobriety tests, are standardized and approved by the National Highway Traffic Safety Administration. That, however, does not mean that they are completely accurate. In fact, each of the three tests has a defined inaccuracy rate.
As explained by FieldSobrietyTests.org, the most accurate of all three tests is the horizontal gaze nystagmus test and its accuracy rate is still only 77%. This test measures an involuntary spasm of the eyeball. Some neurological conditions might interfere with the accuracy of this test.
The walk and turn test is said to have an accuracy rate of 68% and the one-leg stand test is only accurate 65% of the time. For both of these tests, joint or soft tissue problems in the knees, ankles or feet can interfere with your ability to pass the tests. Back problems may also inhibit your ability to balance or walk in a particular fashion. If you are overweight or older than 65, your balance may also be limited even if you have not consumed any alcohol. The combined accuracy of three tests together is slightly higher than each individual rate but maxes out at 82%.
If you would like to learn more about how you might be able to protect yourself and your rights after a DUI arrest, please feel free to visit the field sobriety test inaccuracy page of our California drunk driving and criminal defense website.