All jammed up
The end of petrol rationing has brought back the traffic jam to our cities. Before long there will be complete congestion in some places.
One of the main causes of traffic jams is parked vehicles impeding flow. Another is a consequence of having so many intersecting roads. While science cannot stop people parking their cars, it can do much to improve traffic flow at intersections.
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In the last 30 years automatic travel signals have revolutionised traffic control. First installed in Leeds, they were originally designed to work on a fixed time cycle. More recently, signals have been developed which are operated by the traffic itself, which indicates its presence by running over a rubber pad. But where a number of intersections occur, the limited intelligence and foresight of the ordinary traffic light becomes problematic. A vehicle passing through the intersections may be stopped at each one.
With this in mind, a rather more advanced system has been installed on Oxford Street in London. This groups the lights together so that the traffic flows steadily at a reasonable speed. However, there is still a great deal which could be done to improve traffic control at urban intersections: particularly in the field of detecting approaching traffic. Photo-electric or capacity-operated detectors, which also provide information about the speed of approaching vehicles, would enable traffic lights to be built which could assess traffic conditions more accurately.
The development of such devices would do much to reduce the congestion in cities, but even the best system is bound to cause some interruption in traffic flow. With this in mind, we conclude that the only satisfactory solution is to build intersections with bridges on two levels in all our cities so that through traffic is not impeded.
From The New 杏吧原创, 23 May 1957