The One-Leg Stand (OLS) is a test similar to the WAT test, as it is used to determine whether an individual listen and follow instructions at the same time. In this particular test, the driver is asked to stand with one foot about six inches off the ground, arms outstretched, and count out loud to a certain number. This test is usually performed for a period of 30 seconds. Losing your balance, losing count, forgetting the instructions, putting your foot down too soon or other action is likely to result in a test failure.