Highways and Highway Transportation

by George R. Chatburn

City Traffic.

—Projectors suspended above a traffic officer illuminates him and his semaphore much as spot lights are used in theaters and flood lights to illuminate statuary and buildings. Many of the busy cities are installing color lenses in the towers (crow’s-nests) to regulate the traffic. The colors which are used both day and night are standardized as follows: Red, to indicate “Stop”; amber, to indicate “Change of traffic”; and green, to indicate “Go.”