A width limit is a legal restriction on how wide a vehicle (or its load) can be to travel on a particular road. It’s meant to ensure safe passage, especially on narrow roads, bridges, or through tight tunnels. It refers to the total width of the vehicle including mirrors, cargo, or attachments. Measured from one outermost edge to the other. A width limit is a rule that protects vehicles, road infrastructure, and other drivers by keeping oversized vehicles off roads that are too narrow for them.