What shape indicates traffic regulations or directions?

Traffic regulations or directions are indicated by a rectangular shape. Rectangular signs are typically used to convey a variety of important information to drivers, including speed limits, parking regulations, and other traffic rules. This shape is effective for providing clear and straightforward messaging, as it can display detailed information that a driver needs to see at a glance when operating a vehicle.

In contrast, an octagon is specifically reserved for stop signs, while a pennant shape is used for no passing zone warnings. An inverted triangle commonly signifies yield signs, indicating that drivers should slow down and yield to oncoming traffic. Each shape has a designated purpose, with the rectangular shape covering a broader range of traffic regulations and directions.