<P> In the United States and Canada, there is special signage for lanes that are about to exit, so that drivers who wish to remain on the main road have adequate time to merge . Such lanes are sometimes indicated by special striping ("alligator stripes") and the sign, "Through Traffic Merge Left" (or right). On freeways, the green directions sign for the exit ramp may have the additional notation, "Exit Only," and should have black letters on a yellow background for emphasis . </P> <P> Roadways that only have one entry / exit point - "dead end", "not a through street" or "no outlet". </P> <P> Signs indicating the end point of a roadway . </P> <P> These signs are used to warn drivers of people walking in the street . They may also be used to warn of children playing, playgrounds, bicycle area, deaf child, blind pedestrians, and thickly settled zones where pedestrians may enter the road . In California, United States near the Mexican border, there are warning signs showing a running family . This is to warn motorists to look out for illegal immigrants who try to escape authorities by running through freeway traffic . The symbol was created by California Department of Transportation employee John Hood in the late 1980s . </P>

What class of signs are yellow diamond shaped