INTERSECTION TRAFFIC CONTROL THROUGH COORDINATION OF APPROACH SPEED

THE SMOOTHNESS AND EFFICIENCY OF INTERSECTION OPERATIONS CAN BE IMPROVED BY MEANS OF APPROACH SPEED CONTROLS. A DISCUSSION IS PRESENTED OF THE PRINCIPLES AND THEORIES OF CONTROLLING APPROACH SPEED AND A DESCRIPTION IS GIVEN OF A LOW-COST APPLICATION, TOGETHER WITH A DISCUSSION OF THE FUNDAMENTALS OF THE WELL-KNOWN TRAFFIC PACER. THE OPERATION IS DESCRIBED OF A TRAFFIC FUNNEL WHICH POURS VEHICLES ORIGINALLY SPACED AT RANDOM ALONG A HIGHWAY, INTO THE NARROW TIME PERIOD OF THE GREEN PHASE AT AN INTERSECTION. THERE ARE ESSENTIALLY TWO APPLICATIONS OF THE PRINCIPLE OF CONTROLLING THE SPEED OF APPROACH TO INTERSECTION TRAFFIC CONTROL: (1) THE COMPLETE TRAFFIC FUNNEL, AND (2) THE PARTIAL TRAFFIC FUNNEL. THE COMPLETE TRAFFIC FUNNEL CAN BE USED ON ISOLATED INTERSECTIONS WHERE THE RATHER LONG APPROACH DISTANCES CAN BE ACCOMMODATED. IT CAN ALSO BE USED ON ENTRANCES INTO ARTERIAL ROADS WITH PROGRESSIVE SIGNAL SYSTEMS. THE LOW COST OF SIGNS FOR CONTROLLING SPEED OF APPROACH SHOULD ENCOURAGE EXPERIMENTATION WITH THIS METHOD.