Visual Literacy with speed limits sign

Speed Limit signs shape are rectangles.The layout of the sign is as the following. The speed limit is the middle of the sign so that it's easy to read.

The colors are important. They use black and white. They outline the sign with black and the words and number is black. They fill in the rest with white so that it can be read. The arrangement of the sign is that it is vertical so that when people read the sign its easier to read that if it was horizontal.