TRAFFIC CONTROL,

Star (Christchurch), Volume LXVI, Issue 20260, 21 March 1934, Page 11

TRAFFIC CONTROL,

A New Device Invented in Christchurch.

It is generally agreed that the traffic control lights at Cashel Street do their job well, despite several very obvious disadvantages. The chief of these is the fact that the system does not provide a right-hand turn. The writer investigated recently a system, the production of a local inventor, Mr ,T. A. Sandle, in which all the disadvantages of the present system seem to be o'ver-

come. . The main point of difference with this new system of control is that, while in the Cashel Street case the lights control the traffic, in the new idea the traffic controls the lights. Inserted in the road, on each approach to an intersection, are two pad-contacts spaced according to the requirements of the intersection, but approximately eighty feet apart. The process of operation is as follows: A car on Cashel Street approaches Colombo Street. It passes over the first pad and registers the fact in the mechanism that a car wishes to cross. As soon as the road is clear the driver gets a green signal to cross, and then his wheels cross the second pad, which cancels the signal by delayed action, and provides ample time for the car to get out of the way. The system provides for a stream of cars in exactly the same way, with a time limit intervening to give waiting cars cn other roads the right-of-way. For right-hand turns the system provides two types of green light. The first is a flashing green and permits traffic to travel straight on or to the left. The other is a steady green, and permits traffic to turn to the right, and while this is showing the other lanes of traffic are faced -with a red light. The method of making a right-hand turn is as follows: A car approaches Colombo Street in Cashel Street and wishes to turn south. It crosses the first pad and indicates its intention to cross. The driver may receive a flashing green, and that means that he must pull over toward the crown of the road to allow overtaking traffic to pass. In due course (a matter of seconds) he will receive a steady green, and that means that he can make his right-hand turn sure in the knowledge that the road is clear. One of the big advantages over the old system is that it does not unnecessary v delay traffic. At periods when traffic is infrequent a motorist does not have to wait until the time signal gives him right-of-way, but can proceed almost immediately after his wheels have' crossed the first pad. A more practical of the device under traffic conditions may be possible later on. Undoubtedly, even discounting the right-hand turn, the svstem is a big improvement on the old method.