Here's a couple of YouTube videos on the subject of controlling traffic lights. The first video is for pedestrians. It claims that by clicking the walk button in a special way you can cause the traffic light to change in your favor. This secret code is: 3 short clicks, 2 long, 1 short, 2 long, and 3 short. Sounds like total baloney to me. Of course, if you live in New York City, many of the walk buttons have no effect whatsoever on the signal because they were disconnected decades ago.
This second video claims that it's possible to cause red lights to turn green by using a universal remote control. I'm more inclined to believe this is possible, since I know that emergency vehicles do have devices to change the lights to green. However, you would first have to locate the correct frequency, which would mean standing there with the remote on scan mode until it hits on the right one. Also, you'd need to know the correct code. (The video claims the code is 911.) Finally, would a typical remote control have a strong enough signal? Oh, and it would also be completely illegal.