I personally feel that most of the designs are about self expression. (I made my helmet design). Part of it's functional though, when your on the street you want people (ESPECIALLY DRIVERS) to look your way and recognize your there, to see and acknowledge you. If your wearing all black at midnight theres a good chance a driver is going to look past you and then proceed to pull out in front of you, even with your lights on, it still happens. Flashy and flambouyant gear is part style, part functional.