My idea is to have smart traffic lights. We all have been frustrated as the traffic light only stays green for a short period of time and the line of cars is very long. It always seems like the traffic in the other direction has few cars but yet has the same amount of time that the light is stays green. These smart traffic lights would have camera's scanning each direction determining how many cars are waiting at the red light. The traffic light would automatically adjust the time the traffic light is green based on the number of cars waiting at the red light.
Reward: Email me if the idea gets used.