field sobriety test

Definition from Nolo’s Plain-English Law Dictionary

A preliminary test used by law enforcement officers to evaluate whether a driver is intoxicated. The test is performed on the side of the road where the driver was pulled over, and is designed to test the driver's ability to perform the type of mental and physical multitasking that is required to operate an automobile. The driver is often asked to stand on one foot and then the other, walk in a straight line, touch his or her nose with the forefinger of each hand, say the alphabet backward, and so on.

Definition provided by Nolo’s Plain-English Law Dictionary.