It is well known that driving while under the influence of drugs or alcohol is illegal in Texas and across the United States. However, what exactly constitutes a DWI charge may be less clear. While blood alcohol concentration can play a role in whether you’ll have to face charges for drunk driving, it is not the only factor that is taken into consideration.
Breathalyzers and blood tests are both considered chemical testing, and under the implied consent law, drivers must submit to this type of testing if under the suspicion of drunk driving. For adults, which the law considers to be 21 years for the purpose of drunk driving, the legal limit for a BAC is .08 percent. However, in some instances, even a BAC below the legal limit may contribute to a DWI charge. Conversely, chemical testing is not the only means to determine suspected drunk driving.
While implied consent mandates that drivers submit to chemical testing, a driver may choose to refuse to comply. However, this typically comes with certain punishments, including the immediate removal of driving privileges. Even if a driver refuses chemical testing, an officer may explore other options that do not fall within the implied consent law. For instance, field sobriety tests may be administered, although these are obviously subject to the opinion of the arresting officer.
Field sobriety tests may consist of being asked to walk a straight line or recite the alphabet backwards. However, these may not be entirely accurate, as some medical conditions can cause an individual to be unable to walk in a line or even affect the pupil’s ability to dilate. Despite this, in the absence of a chemical test or when a driver’s BAC is shown to be below the legal limit, an officer may still choose to arrest a Texas driver for a DWI based on field sobriety tests or other observed behavior, such as alleged erratic driving or the smell of alcohol coming from the accused person.
Source: dmv.org, “DUI & DWI in Texas“, , Oct. 4, 2014