When pulled over by a law enforcement official, it is helpful to know what can happen next. When an officer conducts a traffic stop, for example, he or she cannot request a field sobriety test unless you display signs of intoxication. 

An officer has the authority to stop your vehicle and determine the probable cause of a traffic violation. Even the most seasoned driver, however, could swerve or run a red light without any trace of impairment. If the officer suspects intoxication has contributed toward a moving violation, however, you may find yourself performing a field sobriety test. 

An arrest does not occur automatically 

Some individuals fear that if an officer detects an odor of alcohol, it can result in an automatic arrest. Before the car fully stops, some drivers stuff breath mints or gum into their mouths. Doing so, however, could interfere with breath testing equipment and result in a failed chemical test after an arrest occurs. 

As noted by the Vail Daily, an officer initially determines your sobriety by asking questions and monitoring your reaction time. Responding slowly does not necessarily verify impairment; a variety of factors could cause your reactions to appear affected. 

Illness or emotional distress, for example, could hinder your reaction time. An officer generally looks for confusion or difficulty in understanding before asking you to perform a field sobriety test. The officer may not place you under arrest unless you fail the required test maneuvers. 

You may need to perform a field sobriety test 

An officer typically provides an explanation for the traffic stop and the reasons for suspecting impairment. He or she may then request a standard sobriety test including a one-leg stand. According to the Field Sobriety Testing Resource, however, you should not perform a one-leg stand if more than 50 pounds overweight or if you have back problems. 

The standard field sobriety test could help determine a blood alcohol content above the legal limit, but various physical conditions could render the results questionable. Under certain circumstances, an officer’s arrest based on a field sobriety test may allow for contesting a DUI charge in court.