Figure 2.10 When putting out the triangles, hold them between yourself and the oncoming traffic for your own safety. (Soother drivers can see you) Use Your Horn When Needed. Your horn can let others know you're there. It can help to avoid a crash. Use your horn when needed. However, it can startle others and could be dangerous when used unnecessarily. 2.6 – Controlling Speed Driving too fast is a major cause of fatal crashes. You must adjust your speed depending on driving conditions. These include traction, curves, visibility, traffic and hills.