Driving While High: What If You Get a DWI?

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Marijuana use is increasing throughout the country. In fact, 13% of nighttime, weekend drivers have marijuana in their system. These users are 25% more likely to get involved in a crash than non-impaired drivers.


As this increase continues, police are cracking down on DWI marijuana tests to keep our streets safe. If you’re arrested for a DWI, you need to know how to respond.

Here’s what to do if you’re caught driving while high. Knowing how to react will ensure you get the defense you need. Otherwise, you might have to prepare for court on your own. 

Keep reading to learn what to do if you’re caught driving while high.

Effects of Marijuana on Driving

Marijuana contained delta-9-tetrahydrocannabinol, more popularly known as THC. This is the substance in marijuana that causes mind-altering effects. When smoked, the drug passes into your bloodstream, affecting your brain and other organs. 

In addition to the high people associate with marijuana, it can also cause:

  • Mood changes
  • Increased appetite
  • Altered sense of time
  • Drowsiness
  • Memory impairment

However, the effects often vary from person to person. 

Marijuana use can also impair your driving, which can lead to a car accident. 

When you’re driving while high, the marijuana can impair your:

  • Judgment
  • Motor coordination
  • Reaction time

Impairment of these factors can all lead to a car accident.

For example, slow reaction time means you’ll take longer to react to an unanticipated problem. If you start swerving into another lane, you might fail to react quickly enough to avoid a collision. 

On the other hand, marijuana can also make you hyper-focused. You’ll feel intensely focused on some aspects of driving, but disregard other important factors, such as speed or steering. 

An inability to concentrate can lead to a car accident as well. Your lower attention span could cause you to crash or cut through a red light. 

Finally, many people who smoke weed while driving experience difficulty to judge distances. 

Without proper depth perception, you might rear-end the car in front of you.

Testing Methods Used by Law Enforcement

If you use marijuana regularly, only to stop suddenly, the THC will still remain in your system for up to 30 days. 

Regardless, you can only get charged and convicted if there’s other evidence you were driving impaired.

So how do law enforcement officers determine you were driving high? Many states around the country are using an experimental device to test drivers. The device is similar to the near-instant breathalyzer for testing a person’s blood alcohol content BAC.

Here’s how it works:

  • The device includes no electronics (unlike a breathalyzer)
  • A driver’s saliva test sample is self-contained in a sealed package
  • The police officer provides a swab and instructs the driver to swipe it inside their mouth, underneath the tongue
  • The field drug test takes about five minutes to complete
  • The officer collects the swab, seals it in the kit, and reads the results

This device is also able to test for other drugs, including narcotics and prescription medications. These include:

  • Amphetamines
  • Methamphetamines
  • THC
  • Opiates
  • Cocaine

The results are processed by a local lab as well.

Police nationwide are also updating their training on how to conduct safety roadside checks and DUI checkpoints. This will enhance their ability to detect a person’s drug impairment.

The police can also use blood or urine tests to detect the presence of THC in your system. However, these tests can’t determine when you used the drug. It’s also not reliable for determining how much marijuana you ingested or smoked.

As a result, there’s no consensus on how much marijuana in your system indicates you’re impaired.

Signs Police Look For

Drivers with marijuana in their system have increased by 50% since 2007. After pulling a driver over, the police will look for specific signs of intoxication. These signs often indicate that the driver is driving under the influence of marijuana.

The most common signs of driving while high are:

  • The smell of marijuana in the car
  • Slurred speech
  • Glassy eyes
  • Bloodshot eyes
  • Slow motor skills
  • Impaired cognitive function
  • Driving too slowly (whereas drunk drivers often drive too quickly)
  • Erratic driving or weaving

If the police suspect you of driving under the influence, you’ll complete a standard roadside field sobriety test.

Arrested for Driving While High

Even in states where marijuana use is now legal, it’s still illegal to drive while under the influence. The penalties and sentencing for driving while high are the same as the ones for a DUI. In fact, it’s often charged as a misdemeanor.

Your penalty for your first DWI marijuana conviction can include:

  • 96 hours in jail, up to six months
  • A fine
  • Driver’s license suspension of six months
  • Summary or informal probation of three to five years
  • Participation in a drug education class for three months

With each marijuana conviction you receive, the penalties will increase. 

In some cases, a marijuana conviction can elevate to a felony. For example, if you cause an accident that leads to serious injury or death. This can lead to 180 days in county jail, a four-year license suspension, and larger fines. 

Legal Defenses

Make sure to call a licensed attorney. They can investigate your case and protect your rights.

Fighting a DWI offense isn’t like fighting off charges that involve alcohol. Instead, your attorney will first need to review the arrest details to determine if the officer had a valid reason to stop the vehicle. Then, they’ll need to establish a defense around how your marijuana THC level was tested.

Many errors can occur if an officer uses blood or urine testing to determine your THC level. Given these potential errors, many attorneys use this as part of your defense.

There are other ways an experienced attorney can help dismiss your case as well. 

Make sure to choose an attorney who specializes in DWI cases.

Driving While High: What to Do If You Get a DWI

If you’re caught driving while high in Texas, take a breath. Hiring an attorney with the right experience can help you get the case dismissed. Here are the Texas drug laws.

Choose a lawyer who has handled hundreds of DWI cases. Contact us today to learn more about our free case evaluation.