ACROSS

As the previous symbols, this panel does not need an arrow because the drawing of the legs already indicates the direction of the zebra crossing.

TWO WAYS

These two green panels have streets names written on it, and they are placed in the same direction of the street, so will just need to look up at the panels to know which way to go.

EXIT

One of the most known symbol, the exit panel is in every public area, it indicates where is the way out. Normally placed above a door or in front of a corridor, Exit does not need an arrow to indicate the direction.

AIRPORT

This symbol was taken in a train station .

It indicates which platform and which train to catch to go to the airport.

If someone need to know which way is the airport, he will just has to follow this symbol which will bring him there. Thus, it is not an arrow that we need to follow but a simple image of a plane.

HIGHWAY

The highway symbol is generally at the beginning of a road or an intersection.

It is indeed a directional sign because it indicates where the highway begins.

The use of an arrow is not useful. the white drawings already indicate the direction.

A symbol is something such as an object, picture, written word, sound, or particular mark that represents something else by association, resemblance, or convention...