Which factor is NOT a part of visual perception?

Visual perception encompasses various skills that enable a driver to interpret their surroundings effectively. The ability to judge distances involves assessing how far away objects are, which is critical for safe driving. Tracking moving objects refers to the capability to follow other vehicles and pedestrians as they move, helping the driver anticipate actions and respond accordingly. Understanding road signs is about recognizing and interpreting the messages conveyed by traffic signs, which is essential for complying with driving regulations and ensuring safety.

Adjusting the vehicle's speed, however, is not a part of visual perception. Instead, it involves a combination of cognitive decision-making and motor skills, based on the visual information gathered from the environment. While visual perception plays a vital role in informing a driver when they need to speed up or slow down, the actual adjustment of speed is a behavioral response rather than a perceptual skill. Therefore, this factor does not fall under the definition of visual perception itself.