When a motorcyclist taps the top of their helmet, it is a common signal used among riders to indicate the presence of law enforcement or police ahead. This gesture is often used as a warning to fellow riders that they should slow down and exercise caution because there may be a speed trap, traffic stop, or other law enforcement activity in the area.
By tapping the top of their helmet with their hand, the motorcyclist is trying to draw the attention of nearby riders to the message. It is a non-verbal way of communicating the potential hazard without using words or audio signals, which can be difficult to hear or understand while riding.
This practice is prevalent within motorcycle communities as a gesture of solidarity and to promote rider safety. It allows riders to help each other navigate potentially hazardous situations on the road and promotes a sense of camaraderie and mutual support among motorcyclists.