How often have you been at a stoplight waiting for it to turn green and there is no one else on the road? It is 3am and every soul for fifty miles is sleeping except for you and the local police and there you are waiting for the light to change. This waiting shouldn’t be happening.
We should have traffic signals that utilize multiple sensors to see what traffic is currently at the lights as well as the traffic coming down the road from a farther distance. If the traffic lights for a local area are all connected then they can communicate with each other to pass along details about the number of vehicles, speed of travel, and size of the vehicles to the lights nearby. With this information traffic should be able to flow more efficiently by timing the lights so that lanes with more vehicles will have longer green light times. And when a signal senses that there are no other vehicles on the road except for the single person waiting to turn left at 3am it will turn all other lights red except for that person.
The technology is here. By using thermal, video, LIDAR, and many other types of sensors the signals can get a good understanding of the road. May signals are already wired up to communicate with each other so that they stay in sync so there shouldn’t be a need to lay down new wires for the communication. If anyone knows of research already being performed in this area let me know.