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FAQs About BAC Limits for Texas Drivers

Blood Alcohol Content usually, but not always, determines legal intoxication.

In the Lone Star State, BAC usually means blood alcohol content. However, under TPC Section 49.01, BAC could also mean breath alcohol content. That is a minor note that could make a major difference in a DUI defense because it makes the offense easier to prove. More on that below.

The state could use direct or circumstantial evidence to establish intoxication. A Fort Worth criminal defense attorney undermines the state’s evidence in order to successfully resolve these matters, helping people avoid the harsh direct and collateral consequences of DUI.

In most cases, the legal limit is .08 BAC. The state could use one of three tests to prove this limit — a breath test, blood test, or urine test. Blood and urine tests are almost 100 percent accurate, but police officers need search warrants to extract these samples. So, they usually only perform them during high-enforcement “no refusal” periods.

The Breathalyzer is generally accurate, but it has some significant scientific and technical flaws. These flaws could make a big difference in a .08, .09, or other borderline BAC case. More on that below.

Incidentally, officers could arrest defendants if they “pass” breath, blood, or urine tests, and that charge could still hold up in court. .08 is intoxicated as a matter of law, but .07 or lower is not sober as a matter of law. In these cases, the state could use circumstantial evidence, usually FST (field sobriety test) results, to prove intoxication.

Is the Breathalyzer Reliable?

Not really. The modern Breathalyzer is an updated version of the Drunk-o-Meter, a 1920s device. Today’s Breathalyzers are smaller, sleeker, and easier to use, but they inherited the Drunk-o-Meter’s underlying flaws.

Improper calibration is a good example; Breathalyzers are very sensitive devices that require lots of TLC. Furthermore, they are very sensitive to drastic temperature changes, events that are common in North Texas.

Blood/breath estimates might be the Breathalyzer’s biggest flaw. Breathalyzers use breath alcohol levels to estimate blood alcohol levels. Various things could skew this estimate. However, as mentioned, in Texas, BAC could mean breath or blood alcohol level. So, these scientific defenses are unavailable.350

Texas has a zero-tolerance policy for underage drinking and driving. Drivers under the age of 21 cannot operate a motor vehicle with any detectable amount of alcohol in their system.

We should briefly mention that DUI (driving under the influence) is more like OUI (operating under the influence). DUI charges could hold up in court even if the defendant is behind the wheel of a parked vehicle and literally asleep at the wheel.

Texans under 21 can drink while under direct parental supervision and if the parent purchased the alcohol. However, Texans under 21 cannot drive after drinking, even after a champagne toast at a wedding, even if a parent is in the car.

The legal limit for CDL holders in Texas is .04, which is half that of the legal limit for non-commercial drivers.

The limit is lower for CDL holders because of the additional responsibility and danger involved in operating large commercial vehicles compared to personal ones. The penalties are steeper as well. The .04 limit applies all the time. It doesn’t matter whether you are driving your commercial or company vehicle.

Count on a Tarrant County DUI Defense Attorney

DUIs have harsh consequences. For a confidential consultation with an experienced criminal law attorney in Ft. Worth, contact the Law Office of Kyle Whittaker. Virtual, home, and jail visits are available.