Drugged Driving: All About Driving Under the Influence of Drugs in Texas

Many people think of driving while intoxicated (DWI) as an alcohol-related offense, but that is only part of what Texas laws penalize as a DWI. This is known in some other states as drunk driving or driving while impaired, or DUI. There is a legal blood alcohol concentration (BAC) limit for alcohol, but state law also defines "intoxicated" as having one's faculties impaired by alcohol or drugs. That means that anyone who drives under the influence of drugs or controlled substances can also be charged with a DWI in Texas.

Driving with physical or mental faculties impaired is a danger to oneself and others. All states make it illegal to drive under the influence of alcohol and/or drugs, and Texas laws are particularly severe when it comes to sanctions for impaired driving.

It's easier to convict a motorist of driving while intoxicated by alcohol than by drugs because of the "per se" DWI statutes. Texas, like all states, makes it illegal to operate a motor vehicle with a blood alcohol concentration (BAC) of 0.08 percent or higher. This is called a per se violation, meaning "in and of itself". That's because proof that a driver violated the legal BAC limit is sufficient evidence, in and of itself, of intoxication. The prosecutor need not introduce any additional evidence of impairment than the results of the chemical test.

For a drug DWI in Texas, the prosecutor must present evidence that the driver was under the influence of a substance considered a drug under the statutes. They will also need evidence that the driver's physical or mental faculties were impaired. This almost always involves testimony from arresting police officers about how the driver looks, talks and behaves. Chemical tests can reveal the presence of drugs in the person's system, but there is no legal BAC limit for drugs in Texas to show impairment.

​Read More​: DUI vs. DWI in Texas: What's the Difference?

Simply driving with a drug in one's system is not enough to get a driver convicted of a DWI. A driver can only be charged with a drug DWI in Texas if they are found to be intoxicated by the drugs. That is defined as “not having the normal use of mental or physical faculties by reason of the introduction of alcohol, a controlled substance, a drug, a dangerous drug, a combination of two or more of those substances, or any other substance into the body.”

The statutory test is whether the drug impairs the driver's mental or physical capabilities. This can include such drug reactions as sleepiness and dizziness.

Is the fact that a person has a valid prescription for a drug a defense to a DWI? Not at all. This is very important for anyone who drives in Texas to understand. The fact that a person is legally authorized to use a prescription medication does not mean that they can legally drive while using it. If the substance impairs the driver's ability to operate the vehicle, it can be the basis for a DWI even if the drug is legally prescribed.

​Read More:​ Texas's Boating While Intoxicated (BWI) Laws & Penalties

In fact, illegal drugs like methamphetamine, heroin and cocaine are not the most common drugs in DWI cases. The most common drug DWI cases involve prescription drugs like Xanax, Alprazolam, Soma, Vicodin, Oxycontin and Ambien.

It is also possible for a person to be charged with a DWI in Texas if their driving abilities are impaired by over-the-counter medications like Tylenol PM, allergy and cold medicines, and cough medicine.

Generally, a police officer who pulls a car over for erratic or suspicious driving will not know immediately whether the driver is under the influence of alcohol or impaired by drugs. The officer will try to determine whether alcohol is involved by looking for signs like an open container or the smell of alcohol on the person's breath. Then the officer might request the driver to take a breathalyzer test. If the test comes back negative for breath alcohol content, yet the driver seems intoxicated, the suspicion may turn to drug use.

Law enforcement may ask the driver whether they took prescription or over-the-counter drugs. They may ask for details about the type of medication, the dosage and when the driver took the pills. If the officer arrests the person, they may request the driver to submit to a blood test. A driver is legally obligated to consent to a chemical test in Texas.

If they do, the blood test will show the type and amount of drugs in their system. If the driver refuses, they face penalties for doing so, and the prosecutor can use the refusal as evidence in a criminal prosecution. The police may try to obtain a search warrant to force the driver to provide a blood sample.

Drug DWIs are treated exactly like alcohol DWIs in Texas when it come to fines, imprisonment and license revocation penalties. Penalties depend to a great degree on the record of the driver. A first offense receives lesser criminal penalties than a second, and a second conviction is subject to lesser penalties than a third.

What counts as a prior DWI in Texas? If that seems like a silly question, the answer may be surprising. Of course, prior driving-while-intoxicated convictions count as priors. But Texas has a number of similar laws forbidding boating while intoxicated, flying an airplane while intoxicated and even operating or setting up amusement park equipment while intoxicated.

A conviction of any of these offenses is a prior for a current DWI. So a driver getting a first DWI who has two prior convictions for boating while intoxicated will be sanctioned for a third DWI.

A person arrested for a DWI who has never had a prior is charged with a Class B misdemeanor. Sanctions include imprisonment, fines and suspension of the person's driving privileges. For a first offense, the driver faces jail time of between three days and 180 days. The fine may be up to $3,000, with a one-year driver’s license suspension and surcharges equal to another $3,000 if the person doesn't want their license revoked.

If someone convicted of a drug DWI has one prior, the fines and imprisonment time increase since this is charged as a Class A misdemeanor. Fines and surcharges can total $9,000, and the court can order jail time of up to one year and a one-year license suspension. A third offense is a third-degree felony with fines up to $10,000 and a prison term of up to 10 years.

Note that Texas courts can also sentence a DWI driver to mandatory DWI school and, as an alternative to some or all of the jail time, supervised probation that includes community service hours and mandatory use of an interlock ignition device (IID) on every vehicle owned or regularly operated by the individual.

A simple drug DWI can quickly balloon into something more serious if one or more aggravating circumstances are present. Something as inconsequential as having an open container of alcohol in the vehicle can lead to increased penalties. Having a child passenger under 15 in the vehicle can transform a misdemeanor into a felony with a fine of up to $10,000 and a prison sentence of up to two years.

If someone whose ability to drive is impaired by drug use and causes an accident that results in serious harm to another person, it is a felony called intoxicated assault. If the DWI driver causes the death of another person, it is a felony called intoxicated manslaughter. Both carry significant fines and potential imprisonment.

​Read More​: Is a DWI a Felony in Texas? All About Felony DWIs