UNIQUE SAFETY SIGNAL

Evening Star, Issue 22515, 7 December 1936, Page 5

UNIQUE SAFETY SIGNAL

SPEED ON BENDS An automatic signalling device which seems to possess definite possibilities is now being tested thoroughly in Baltimore (U.S.A.). Recognising that many drivers are unaware of the speed at which they travel around curves, the inventors of this new device have designed it to ensure that motorists observe ■ a safe speed. The apparatus is electrically operated on lines similar to the system used in some automatic traffic signals employed at intersections. It consists of three major units—an illuminated road sign, which shows the sale speed for negotiating tiie turn, a traffic light with two fapes suspended high above the centre of the road, and showing two illuminated discs facing the traffic travelling in each direction, and a sound detector which is embedded in the road in such a way that motorists must pass over the sound chamber. This sound chamber is rectangular in shape, and it contains a microphone, which picks up the sound of the tyres passing overhead and converts the sound waves into electrical impulses. These are conveyed by wires to a timing mechanism, which in turn operates the signal lights suspended centrally over the road at the danger point. OPERATION OF SIGNAL. If the motorist passes over the sound detector at the safe speed as shown by the illuminated sign at the, side of the road, the traffic light will turn from red—“ Stop ”■—to amber—“ Slow ” before he reaches it. thus informing him that he may proceed. Should the driver cross the sound detector at a dangerous speed the indicator will remain red, and he will have to stop and wait for a pre-determined time—presumably set by automatic mechanism within the device—when the signal light will change to amber, and he may go ahead. Failure to take notice of the warning conveyed by the signal will result in a heavy penalty. Another feature of the device is that when a line of closely-following cars approaches the sign at the prescribed safe speed the signal will display the amber light until a gap occurs; then it will revert to red. The habit of many motorists of cutting blind corners is recognised in another of this new signal, for the detector in the other approach to the curve warns motorists of the approach of cars from the opposite direction. The device thus allows motorists to negotiate the curve at only the safe speed, and also warns them of vehicles coming in the opposite direction. DISTINCT POSSIBILITIES. Most of the fatal accidents in country districts _ are caused by drivers, often unwittingly, taking corners too fast, so that their cars are thrown off the road by centrifugal force. It is considered that this new signal, in principle, is a very important contribution to the task of making the highways safer, and it will be interesting to see the result of the very careful trial to which it is now being subjected. Presuming that it does everything claimed for it, the only objection to its extensive use on country roads seems to he the obvious one of expense. It would he hoping tor too much to see it in use on every blind main road corner. There are, however, certain notoriously dangerous curves where its use would be a very great blessing to the motoring public.