Perceiving movement and calculating the time it takes for one object to strike another object is an inherently complex operation. Those who are very good at it can become successful baseball or tennis players. But we all have to do it. Whether driving on I-75 through Macon, or on winding Georgia state roads, every time you drive a car, your brain is making unconscious calculations when you change lanes, merge or make a turn.
The brain uses the data received from your eyes and the size of the object on your retina to complete part of the calculation. However, it also uses "rules of thumb" such as artist's depth cues that function as a shortcut in figuring out distance. For motorcycle riders, this has a consequence that drivers may perceive them a further away, resulting in a motorcycle accident when they pull out in front of them.
Research has found that people repeatedly picked the smaller object as being further away in tests even when it was closer. Because motorcycles appear smaller relative to a passenger vehicle or pickup truck, the brain appears to be fooled into believing they are further in distance.
While "seeing motorcycles" is important, if the brain calculates that the motorcycle is further away than it really is, because it is using a depth cue of relative size, the education of drivers will have to do more than simply to get them to see the cycle.
Drivers will have to be taught to use more caution than normal when they see a motorcycle, because they cannot rely on the brains normal automatic calculation.
Source: Claims Journal, "Vehicle/Motorcycle Accident Link to Brain Miscalculation: Study," September 10, 2013