Taking a bicycle can be the healthy and green thing to do, but it can get pretty dangerous for the cyclist especially in the dark. The DIY Turn Signal Biking Jacket works by blinking the arrow in which the direction you want to turn. Of course, it works best against a dark background which could potentially lower your overall visibility when not using the turn signals. Ah well, I’ve always wondered by bicycle manufacturers did not bother to come up with turn signals for their rides. How much more expensive could it be, really?