Drivers who are pulled over for DUI / DWI in Fort Bend often must perform field sobriety tests before being arrested. The walk and turn test is one of three standardized field sobriety tests recognized by the National Highway Traffic Safety Administration (NHTSA). However, contrary to common misconceptions, the test isn’t used to evaluate the driver’s level of intoxication – it is used solely to establish probable cause for an arrest and to create evidence for a drunk driving court prosecution. Fortunately, field sobriety test evidence can be aggressively challenged. An experienced Texas DUI / DWI lawyer will effectively cross-examine the arresting officer and create reasonable doubt in the driver’s guilt.

The walk and turn test is administered in two parts – the driver must first stand heel-to-toe with arms down while receiving the instructions. The officer will direct the driver to take nine heel-to-toe steps along a real or imaginary line, turn, and walk back toward the officer in the same fashion. As the test progresses, the officer notes any signs that suggest that the driver is impaired.

The signs of impairment that police look for are an inability to maintain balance during instructions, beginning the test too soon, pausing while walking, an inability to touch heel to toe, veering off of the line, using the arms to balance, losing balance during the turn or inability to turn correctly, and miscounting the number of steps. If two or more of these signs are displayed, the officer will conclude that the driver has a blood alcohol content (BAC) of .10 percent or greater, and an arrest for drunk driving will follow.

Like other field sobriety exercises, the walk and turn test is a divided-attention test – it’s designed to assess mental and physical impairment by requiring the driver to focus on two tasks simultaneously. Regardless of how the driver performed, the prosecutor will use the results as circumstantial evidence that he or she was under the influence of alcohol or other drugs.

However, the physical impairment demonstrated by many accused drunk drivers during the walk and turn test can be caused by physical conditions other than alcohol, including illness and injury. Alcohol use triggers both mental and physical impairment, and mental impairment always occurs first. Drivers with a high tolerance for alcohol can mask physical impairment, but mental impairment cannot be disguised. Therefore, if a driver showed only physical impairment, field sobriety test evidence can be successfully challenged.

The walk and turn test is particularly challenging for drivers with back or leg injuries, individuals older than 65, overweight people, and drivers with inner-ear disorders. Taking the test on uneven ground or while wearing high heels will also impact a driver’s performance.

Police sometimes don’t even conduct the walk and turn test properly, or don’t interpret the driver’s performance correctly. A Texas DUI / DWI criminal defense lawyer with a proven track record of challenging driving under the influence cases will establish whether factors unrelated to alcohol use impacted the driver’s performance on the walk and turn test, and challenge the results accordingly.