There is a host of information available on the roadways, directing the flow of traffic and the interaction of the driving environment. The shape of a road sign can tell you as much about the sign's message as its color. Every driver needs to be extra careful when the weather is bad or when changing lanes, turning on a red light, passing, approaching intersections or merging into traffic. Always be alert to what is happening on the road. You must know and understand these signs and respond correctly when you see them on the road.