1. Fog, external to automobiles, is listed in the top 20 causes of auto accidents in the United States.
2. Fog, on the inside of automobiles or motorcycle face shields, causes the same level or worse conditions (shorter depth-of-field viewing) as thick fog outside of them.
3. While fog on the inside is not listed as a top cause for accidents, most people are not going to admit that fog caused them to have an accident out of fear that they could be brought up on charges for negligence or have an increased insurance premium or legal liability, and that leaves inside fog build-up as a silent killer. While it may seem that common sense would dictate that a person wouldn't drive/ride/fly with fog build-up on the inside of a viewing surface, that's an unsafe assumption when compared with their need to get somewhere for any number of human motivating factors that outweigh the risk of fog in a human's mind.
4. Of the top 20 causes of automobile accidents in the United States, fog building on the inside of these viewing surfaces can cause the same effects as as the majority of the other causes that are listed, as follows:
a. distracted driving (trying to wipe windshields/face shields)
b. intoxication (reaction time hampered by limited visibility)
c. speeding (not paying attention to speed because of preoccupation with visibility due to fog)
d. reckless driving (while potentially completely unintentional, can easily result from limited visibility and preoccupation with clearing visibility)
e. in this same format, fog on the inside of these viewing surfaces can lead to or mimic running red lights/stop signs, wrong-way driving, unsafe lane changes, driver fatigue or general impairment, night driving, improper turns, tailgating, under-estimating deadly curves, failure to see animals at animal crossings/humans at pedestrian crossings, or tire blowouts from not seeing objects that might puncture tires, including potholes.