whether you're in the air on land or sea there are devices to protect the safety of the traveler speed with safety is the tempo of all modern transportation flashing beacons guide airplanes from port to port on the water the lighthouse guide ships safely to the harbor on land trains thunder over the rails safely guided by signal light all over the world control of traffic with safety is of first importance wherever people travel from one place to another in asia europe africa and the far east it makes no difference whether the traffic is fast slow heavy or light traffic is directed to guide vehicles safely along the way the language is very different customs change when boundary lines are crossed traffic signals mean stop and go in any language and in america today those great highways stretch across the country the motorist is never away from traffic control sooner or later he comes to a city with its crowded street where traffic police are the finest in the world and traffic moves under positive state controlled streets of the united states are crowded with fast moving automobiles added practically every city in town today the motorist finds traffic lights to aid him on his way but those premiums on drivers are like all the automatic traffic signal both of times when they use it well i'm treated right they are saving time and making it possible for everybody to get on fine after and move along in traffic with less wear and tear with safety first i've gone always in their minds the traffic bureaus throughout the country everywhere have given motorist guidance up signal lights to tell them when to stop and tell them when to go am safety there are many types of signal lights used in traffic control today some towns use lights with only two colors while other towns use three colors and still others have traffic control built around a four color system in some cities the lights are so arranged that drivers must stop on the amber lights in other towns drivers make goal amber and green in still other communities the amber light alone appears on both sides at the same time some cities have lights which are augment it by some a fo in other cities the lights look like little houses hanging from wires even no traffic engineers are working with safety councils for the national standardization of the traffic signal system and there is every prospect that as soon as it is feasible motorists will travel from border to border and from coast to coast and meet the same old prem with the same clear message all the way traffic lights pla no favorites the traffic signal puts you level with the world and keeps you even with safety regardless of what car you drive and although the perfected hydraulic brakes on modern motor cars will bring the car to a smooth quick stop racing light his heart of the tires as well as on the nerves automatic traffic signals wait for no driver today's car is fast on the getaway but the safe driver doesn't race doesn't try to beat the signals and the careful driver never rides the amp all automatic traffic signals have minds of their old let's open up this little iron box near the bottom this is the traffic signals brain it controls the three colors red and blue or and green let's simplify it to see how it works first there's an electric motor which operates on current from an ordinary electric power line the motor drives the train of gears which reduces the speed and slowly terms of shaft this shaft carries some little wheels called cam these cams are the thinking mechanism of the traffic lights brain let's look at one of the cams to see how it can throw the light as the cam turns it touches a small metal contact strip this completes an electrical circuit and the stop light goes on as the cam turns around it moves away from the contact strip no more electricity can flow through the circuit and the light goes out at the same instan another cam of the same shaft is just touching another contact strip and the goal light turns on the cams are arranged so that the stop and go lights alternate or change direction each time the shaft goes around the controls for all lights on the signal box work on the same principle when the red light is on for say the main street the green light is on for the side street and the amber light is off before the lights change the amber light comes on for both the side streets and the main street then the side street green and amber lights go off and the red light goes on the main street red light goes off to be replaced by the good old green light this is all very simple but the next thing is to get traffic lights different timing to take care of different traffic requirements one set up traffic lights run on schedule these schedules are the result of careful planning by experts who study traffic conditions at the location of each signal light for example if not south traffic is much heavier that east west traffic the schedule is arranged to give more green light time to the heavier north south traffic the scheduling of groups of lights is a bit more complicated let's examine the method of controlling groups of signal lights one method of time all lights to operate together first of all know what some cars move while east west traffic homes in the entire section then as the lights change east west traffic is given right of way our the system will not work in all locations since all rights work together it is impossible to get extra green right time if there is heavier traffic on certain main streets so on some main thoroughfares plaxico progressive system permitted adjustment for heavy traffic and alone main boulevard traffic to move steadily without stops in order to get the greatest advantage from the lights the driver must time his speed to the schedule of the light the driver who tries to go too fast as to stop at each other section to wait for the light to change the green lights won't hurry for anyone but the driver who fits his speed to the schedule of the light keeps moving comfortably and safely stuff when the signal says stop when the signal says wait and go only when the signal go the safest way to drive and the best way to make time is to hear your driving in with the light being green all the way