This might be good as a supplement to current signals at intersections with heavy traffic. A couple design issues stand out that prevent it from replacing conventional lights. One is that people who are red/green colorblind may have a problem with the design because it does not have separate heads for red and green. On traditional lights in most countries, red it always on the top, and green always on the bottom, or on sideways mounted lights, red on the left and green on the right (for countries that drive on the right side of the road; left drive countries are usually opposite). Also, the fact that the green light and red light are in different positions is considered a design feature. Seeing one light go out, and a different light come on make it more obvious that the signal has changed. Where this light would stand out is in a downtown area where the lights are synchronized at a certain speed. Adding this, in addition to current signals, would help communicate how the signals are synced and perhaps improve traffic flow.