THE NEW RAMP

Evening Post, Volume CXXVI, Issue 150, 22 December 1938, Page 10

THE NEW RAMP

NO RIGHT-HAND TURNS

PENDING LIGHT CONTROL SYSTEM

HUTT ROAD & AOTEA

QUAY

In view of the dangers which would be introduced, particularly during the holiday period, by the making of righthand turns to or from the ramps from the Hutt Road to the new overbridge, it is probable that such turns will be prohibited, pending the installation of a system of light control of traffic.

It is not likely that the rule will be permanent, for, as stated yesterday, a great part of the value of the work — and of the money spent upon it—will be lost if the most effective use is not made of the facilities the overbridge offers, but there is no question about the risks which would follow were lorries and cars to cut across the main lines of traffic on the Hutt Road. The intersections are such, moreover, that manual control, pending the delivery of the light control equipment, would be extremely difficult, if it were possible at all. The delay in the ordering of the equipment is regrettable. TYPES OF LIGHT CONTROL SYSTEMS. The first traffic lights installed in Wellington (actually the first in New Zealand) were . those at Courtenay Place, the corner'of Willis and Manners Streets, and at the Bank of New Zealand corner. These are time-cycle lights; a clock controls the changes from red, through amber, to green. It is a flexible sort of clock, with a wide range of possible time cycles, but it is inflexible in that when a cycle is fixed it carries right ahead, whether the traffic volume is light or heavy, or whether nine cars run north and only one south. The next step in development of light control equipment was the trafficactuated, or electromatic, system of control,, The first of these lights (again the first in New Zealand) were those installed at the Queen's Wharf gates. •" Everyone knows the general principle of this system: cars run along Jervois Quay freely until some-' thing comes in from the side, either to or from the wharf gates, presses a pad and changes the light signals. This system takes an-intelligent interest in actual traffic requirements, (Pedestrians can also control the lights, if they prsss the button to stop the flow in Jervois Quay while they cross, but this is an addition to, and not a radical alteration of, the traffic-actuated system. Another form of pedestrian control is in operation at the Maritime Building crossing: here vehicular traffic runs without hold-up until a pedestrian presses the button; there are no traffic pads here.)

LIGHTS THAT SORT THE TRAFFIC

The problem at the overbridge will be more complicated /than at any present light control point. Take the case of cars and trucks which are running over the bridge from Aotea Quay to the Hutt Road. The majority of drivers will want to continue right ahead towards Kaiwarra. A few will want to turn (by right-hand turn) back towards Thorndon Quay; these are the people who introduce all the bother. How can traffic pads sort out the Kaiwarra-bound from the Thorndon Quay-bound? It is not elementary, but it is not particularly difficult of design, though there are plenty of catches in the building of the equipment to stand up to the racket of traffic pounding and weather damage. The sorting can be done by employing a double set of pads. On running down the ramp towards the Hutt Road the car or' truck will pass over one pad. It will set a train of electrical thought under way. If the car carries right ahead (as it will if no right-hand turn is intended) it will pass over a second pad which will cancel the first message before the lights have time to begin their change. But the driver who is proposing a turn will stop short of the second pad until the lights do change. Traffic on the main flows, north and south on the Hutt Road, will be stopped by "red," and he will make his turn, with a clear roadway to make it in.

That, at any rate, was the system proposed when the lights were discussed a year ago. Several variations have been" proposed since then, and it may be that one or other may be adopted to reduce the cost of the equipment, but," however it is done, there is now general agreement that there must be control by a definite light system.