Universal Hand Signals
Whether riding in a group or riding alone, hand signals are critically important to your overall safety. Motorcycle safety using hand signaling lets the other people (mostly automobiles) around you know what you are doing. Turn and brake lights are small, and often not familiar to automobile drivers. Hand signals greatly increase your visibility and over all safety. Hand signals are really important when riding in groups, because of the limited visibility of the riders behind you, but equally important when sharing the highways with cell-phone talking, or equally distracted drivers who likely don't even know that you are on the same road with them. Studies show that many drivers of cars and trucks don't "see" motorcycles. Hand signals and Harley's loud pipes save lives.
In motorcycling, hand signals are extremely important; not only when riding in groups of motorcyclists but also when riding in traffic with cars and trucks. It is always a good idea to give the automobile drivers as much visibility about your intentions as possible.
When riding in a group, the person behind you likely does not know what's going on ahead. The courteous rider will relay signals back through the pack.
Start Engines
Left Turn
Right Turn
Hazard Left 
Hazard Right
Speed Up
Slow Down
Single File
Staggered Formation
Tighten Up
