Confused

So I was on my way home from work yesterday when I saw a guy on a motor cycle in front of me on the off ramp. He was wearing one of those REALLY lame mohawk helmets , but what confused me is that his license place was a handicapped plate. I'm sorry, but I'm confused. If you are handicapped how can you ride a motorcycle? According the the DMV you must meet one of the following criteria:

*Heart or circulatory disease.
*Lung disease.
*A diagnosed disease or disorder that significantly limits the use of lower extremities.
*Specific, documented visual problems, including low-vision or partial-sightedness.
*The loss, or loss of the use, of one or both lower extremities or both hands.

I suppose that he could've had lung disease or some heart problem ... but he looked young. Wouldn't you think riding a motor cycle would be too stressful/dangerous if you had a heart condition. I guess I just can't imagine my gramps with his oxygen tank cruising around on a motor cycle wearing a mohawk helmet.

Just weird.