i remember seeing something on tv about u turn slots... the concept daw is to keep the flow of traffic constant, kahit na medyo mabagal... compared to stop lights na mas mabilis nga pero patigil-tigil naman, and nagkaka-problema pa minsan kapag high volume of traffic and cars are still in the middle of the intersection when the lights change. i think it was BF himself who was being interviewed about this... makes sense to me