Haven't seen a 'buhos' flow of traffic coordinated with the help of traffic lights. Considering that, its imperative that communication between the traffic enforcers stationed at different lengths of the highway is clear as to direct the halted direction properly, as well as have a standard definition of how heavy traffic volume is. Intersections should also be kept open at all times by motorists; shouldn't really be watched over by the enforcers ideally. I don't make use of Alabang-Zapote road that much to notice much of a difference, but from what I've observed, whenever one direction of traffic is light, this scheme is feasible.