Green, Yellow, & Red
Everyone could use a traffic light to relieve stress.
The History of the Traffic Light
The traffic light was invented in 1920 by a police officer concerned with the increasing amount of cars on the roads and how dangerous it was getting. Traffic lights helped organize chaos in busy streets especially like in New York, which is where The Great Gatsby takes place. Before traffic lights there were pedestrians, bicycles, cars, horses, and all kinds of things on the roads
From the beginning of the book you notice how chaotic everyone is. Most of the characters from East Egg are very wealthy people who are simply bored with their lives because they have everything they could possibly want and if not, it's not hard for them to get it. With boredom comes trouble. If the people on Long Island had a traffic light in their life they would have been able to organize the uproar.
How It Would Be Used
Daisy definitely could have used a traffic light to tell her when to slow down, stop, and go. This could be directly related to when Daisy hits Myrtle in Gatsby's car so that she wouldn't have ruined Gatsby's life and got him KILLED. When Gatsby is explaining what happened in this moment he says, "Anyhow---Daisy stepped on it. I tried to make her stop, but she couldn't, so I pulled on the emergency brake." If there would have been a traffic light in this moment Daisy would have noticed the bright red light and stopped before it was too late.