Which factor does NOT typically affect the results of a field sobriety test?

The presence of passengers in the vehicle is a factor that does not typically influence the results of a field sobriety test. Field sobriety tests are designed to assess an individual's physical and cognitive abilities in the context of their potential impairment due to alcohol or drugs. This assessment is primarily focused on the person's individual ability to perform tasks such as balancing, following directions, and other motor skills.

In contrast, factors like the physical condition of the individual can heavily impact test performance. For example, someone with a medical condition or injury may struggle with tasks regardless of their sobriety. Weather conditions, such as rain or wind, can also make it more challenging for individuals to perform tests accurately. Lastly, previous driving experience might influence an individual's confidence or behavior in an impaired state but does not directly impact the mechanics of how the field sobriety tests are conducted or evaluated.