Do Police Drug Test for Weed at Roadside Traffic Stops?

Now that marijuana has been legalized in California, the police force has had to come up with a way to tell if people are driving under the influence.

Since there are no straightforward tests to determine if someone is under the influence of marijuana while driving, this has caused police to create some very interesting ways to test this.

If you live in a state where marijuana isn't legal, having it your system or in your car is an offense. But, officers are now working on a drug test for weed to see if those they pull over are under the influence.

Read on to find out what happens if an officer suspects you're under the influence.

The Breathalyzer

Currently, there is no breathalyzer test to determine if someone is under the influence of marijuana. This is because the amount of marijuana in your system doesn't necessarily correlate with your impairment. THC is not the same as alcohol, in that how much you're impaired is measurable by a drug test.

However, a doctor in California has invented a marijuana breathalyzer to use on people who they suspect are under the influence. At this moment in time, it is not used by the police and no one is sure if it ever will be.

If a police officer suspects you're under the influence, he or she may get you to take a breathalyzer, but it will most likely be to test for alcohol.

Urine Test

In the state of California, you automatically consent to a urine test if the officer on duty believes you may be under the influence. You may be asked to provide a urine sample if the officer believes you're driving while high.

But, this has its flaws as well. The issue with this test is that THC can stay in your system for several days after you've smoked it. So, it won't necessarily hold up in court on its own. Instead, the officer will also have to prove you failed a field test or had other appearances of being high.

Because it stays in your system so long, it is categorically unfair to say that you're high just because you test positive for marijuana. You may have smoked 2 days ago, and are perfectly sober, yet the markers are still present.

Mouth Swab Test

A mouth swab test is also another way officers can test to see if you have THC in your system. This is usually the first line of defense test if they feel your behavior warrants it.

You can find out more about mouth swab tests and how they work.

These tests are, unfortunately, not completely accurate either. As such, officers cannot use them to prove that you're high and cannot charge you with a DUI due to this alone.

Again, this test may show THC that has been in your system for several days, and as such, you may not actually be high at the moment.

Blood Test

A blood test is typically the second line of defense. Again, the blood tests have the same pitfalls of the other tests, in that they do not give an accurate picture of how much THC is in the driver's system at that exact moment.

Field Sobriety Test

The field sobriety test, or FST, is what most police officers now rely on to tell if someone is under the influence. You've probably seen this test on television or in the movies if you've not seen one of your friends have to take it.

This famous test involves walking a straight line, standing on one foot, touching your finger to your nose and estimating time. These coordination skills are those needed for driving, so if a police officer feels you lack this coordination, they may suspect you are under the influence.

Physical Symptoms

Part of the field sobriety test includes testing physical symptoms. This cursory test performed by an officer will help him or her determine if they feel you're behaving erratically based on a medical problem or if you're under the influence. Some causes for erratic behavior may include a concussion, diabetic shock, and other illnesses.

The officer will proceed with the field test if they believe that your behavior cannot be chalked up to anything medical.

The officer will also have you follow a pen or his or her finger with your eyes while keeping your head still. If your eyes jerk, this is known as horizontal gaze nystagmus and can be attributed to drug or alcohol use.

They will also look at how big your pupils are. The size of your pupils will tell the officer a lot, and whether they need to call an ambulance or issue you with a DUI. Pupils that are dilated, but not so much so that it is medically alarming, can indicate that you've taken an opioid or an "upper."

Drug Tests for Weed on the Road

Currently, drug tests for weed are in their infancy. The University of California at San Diego has been extensively studying the effects of weed and driving and how it may impair your reflexes. One day, they may reach a conclusion in which policemen and women can tell categorically if you have too much weed in your system.

But, at the moment, they must rely on the field sobriety test, your eyes and how they look, and fairly inaccurate drug tests. Because of this, it is very difficult for an officer to deduce that you have been smoking weed prior to driving your vehicle.