We all know that if someone gets pulled over and is suspected of driving drunk, police officers can administer a breathalyzer that will analyze the amount of alcohol in your system and determine if it is over the legal limit. Unfortunately, people who are willing to drive impaired don’t stop with just alcohol, so is it possible to do roadside tests for other substances?
The answer is, not really. Marijuana can linger in a person’s bloodstream for weeks after they last ingest it, meaning that it’s impossible to tell from a blood or urine test whether someone is currently under the influence. They can, however, perform what is called a field sobriety test, or a series of mental and physical tasks meant to determine if you are intoxicated (think walking in a straight line or touching your nose with a fingertip). There are a variety of field sobriety tests that might vary from place to place, so we’ll use California as an example. In California, there are three standard types of tests.
The horizontal gaze nystagmus (HGN) test is the most accurate, and it is also admissible in most courtrooms in the United States. Because the brain and the nerve centers that control the eye are affected by marijuana, one way to determine impairment is to test the way the eye follows a moving object. If the eye is unable to track the object while it is moving at a constant speed, this is called lack of smooth pursuit. Another method involves testing when a person’s eye will begin to jerk as it moves at an angle.
The walk and turn or walk the line test divides the subject’s attention. You’ll be asked to take nine heel-to-toe steps in a straight line in one direction, then turn on one foot and walk heel-to-toe in the other direction. The officer administering the test will be watching to see whether you can maintain your balance, whether you begin walking before the officer finishes giving you instructions, whether you stop walking or use your arms in order to regain your balance, whether you actually touch your feet heel-to-toe, whether you lose your balance when turning, and whether you take an incorrect number of steps.
Finally, the one leg stand test requires you to stand on one foot without swaying, hopping, using your arms to balance, or putting the other foot down.
You are not legally required to take any of these field sobriety tests, although an officer may still arrest you if they think they have probable cause for a DUI. In California, if you’ve been pulled over but not arrested, you can refuse the tests. If you are arrested and continue to refuse, you will lose your license for at least one year. Refusal also allows the police to hold you for 48 hours.
If you or a loved one need help with quitting drugs or alcohol, consider Asana Recovery. We offer medical detox, along with both residential and outpatient programs, and you’ll be supervised by a highly trained staff of medical professionals, counselors, and therapists. Call us any time at (949) 438-4504.