From the caveman directing his domestic animals, every improvement has meant more and faster traffic to control--and the caveman analogy indicates the level of this presentation. The obvious purposes of road signs, markings and traffic lights are noted, ditto some of the reasons for different laws in different states. There's no expertise, and little precision: a chapter on building roads mentions three types of pavement (black top, macadam and concrete) without differentiating among them, and the glossary at the end wrongly defines the first two identically. More generalities about policemen in general and about punishment for infractions precedes a nod to railway and airway problems. Any youngster who keeps his eyes and ears open knows as much.