It is most important to flash your brake light when:

A motorcycle's single brake light is not as noticeable as the two larger brake lights of a car or truck. It can be a good idea to flash your brake light to help others notice it, especially when you need to slow down more quickly than surrounding drivers may expect.

• Passing another vehicle.
• You will be slowing down suddenly.
• There is a stop sign ahead.
• Your signals do not work.