BLIND SPOT.

Auckland Star, Volume LXVII, Issue 59, 10 March 1936, Page 18

BLIND SPOT.

THICK PILLARS. CAUSE OF ACCIDENTS. PRACTICAL TEST. Man has two eyes! An obvious statement indeed, but the designers of our motor car bodies seem to forget it. If they did not,. surely they would see to it that the beautifully simple manner in which man is able to see round a solid obstruction, provided that obstruction does not exceed a certain size and shape, was not nullified by their faulty design. A man's eyes are situated approximately apart. Let us try to realise clearly what this means. If the front pillars of a car, plus window edging, do not exceed 2iin in width, it is as though they were not there when looking straight into the distance past them. In fact, they cause jio obstruction to the distant view at all. Now, consider what happens if the pillars arc thicker than this. The amount of view that is blocked out depends on the excess of width over 2Jin, and on one's distance from the pillar. If, for instance, one takes the case of a pillar Sin thick, and assumes that one's distance from it is 18in, than the size of an object 20 yards away that can be hidden is roughly 20in, i.e., the size of an ordinary pedestrian. But if the pillars be 4in thick—not at' all an unusual size nowadays—then the size of the object that can be concealed at 20 yards is 60in in width, the size of a small car seen head-on. Similarly, at 40 yards a 4in screen pillar can conceal an object about 10ft wide, i.e., a motor

bus head-on; whilst at 100 j-arda it would conceal an object roughly 25ft broad, i.e., the whole width of a main road. These calculations are really rather surprising to anyone who has never thought of this point before. To those "who are interested: "Drive your car out into the country and stop it somewhere "where you have a clear view for a little distance on each side, and try it for yourself—unless, of course, you are one of those lucky ones who have a car with a narrow screen pillar, in which ease you are fortunately unable to try it. Be careful to keep your head still whilst carrying out the test." It should be noted that the nearer one is to the windscreen the larger is the size of the blind area, if present. In this respect some of the ultra-modern cars with sloping windscreens are particularly bad. * Most drivers do not notice the existence of this blind spot because they very seldom approach any object, or are approached by any object, in a straight line with the screen pillar. But the very fact that the average driver docs not notice the blind spot constitutes its chief danger, because it means that occasionally at cross-roads and on curves, corners, i.e., some object will be seen an instant later than it would otherwise /lave been. This can easily occur as the result of the combined movements of one's own cp.r and of the other object J keeping that object for a few instants in the same relative position beyond the sci een pillar. Also, and this is an important point, this occurs at places where the driver is sure that he has an unobstructed view. Of course, a moment later the driver sees the concealed object, 'but we all know what a difference split seconds may make. How many "inexplicable" accidents are due to this cause ?