DRIVING ABILITY.

New Zealand Herald, Volume LXVIII, Issue 20820, 12 March 1931, Page 17

DRIVING ABILITY.

THE HUMAN ELEMENT. This graphic account of the tests one has to go through in England, in conforming to the new Act, indicates a stringency in' tlic regulations which should, in time, result in a higher standard of driving. With the number of cars on the road in the Old Country, accidents are unavoidable and bound to bo numerous, but every precaution that is taken will undoubtedly result in a lessening of road crashes and subsequent fatalities or injuries.

i' Hairbreath cornering," a wild rush through fog, and a head-on collision with a church—such were ray first experiences when, inspired by tho new Road Traffic Act, I sought the opinion of tho National Institute of Industrial Psychology as to my physical and mental fitness to drive a car.

The tests to which I was submitted at tho institute have been in process of development for the last twelve months, but it is now believed that satisfactory indications can be obtained both of tho " potential driving safety" of an individual and of tho amount of wear-and-tear which he is likely to cause to tho vehicle driven.

Tho realistic test which led to my first undoing is an .entirely new production of the institute's staff. The " driver "is seated in what, to all appearances, is an ordinary car. Ho clasps a regulation steering column and beneath his feet are an accelerator pedal and a brake. But in front of him, and corresponding to a windscreen, is a sheet of whit© material on which appear? a changing pattern of roads and obstacles. This effect is produced by a platform, which moves in accordance with the steering wheel and embodies a miniature world which, seen from outside tho car, is in curious contrast to the very real emotions induced in the " driver." _ The church is made of cardboard and is about two inches long, while trees prove to be simply constructed of lamp-wicks and sealing wax. Peculiar Illusion.

As this platform moves about, a diminutive car, equipped with headlights, but actually stationary, runs an erratic course along tho miniature roads. Tho picture projected on the " windscreen " is thus tho actual area of tho miniature world, which is illuminated by the headlamps of the miniature car; and the driver is directly responsible for all that happens in the picture. The illusion produced is extraordinary, and, when the " car ran off the road on to the rough grass at the side, I was firmly convinced that I was being severely jolted. . When an accident occurs a bell rings and a lamp lights up on the dash-board to instil further caution in the driver, further, when the design-is completed, there will be a drum which will record the driver's course and his reaction to particular emergencies. At present he has no moving traffic to contend with, but it is proposed to provide future inquners with an opportunity for a " surprise collision with another car. _ My steering and capacity for nignt driving having been satisfactorily disposed of, we proceeded to a test involving judgment of relative speeds. This consisted of two model railway tracks which cross obliquely four times in tho course of a complete circuit. On one of the tracks there is an engine moving at constant speed. The speed of the other could be controlled by a lever which I was given to operate, the instructions being that I was to drive it as rapidly as possible, while at the same time avoiding collisions with tho other engines.

ENGINE AS A BRAKE. One of the practices which are gradually going out of use in England is that of employing the engine as a braking medium. In very hilly districts reliance is still placed upon the retarding effect of the engine when an indirect gear is engaged. On the level road, on the other hand, the higher modern standard of frictional braking has cut out a lot of use of tho engine for retardation. iU'om the point of viow of tho maintenance engineer there is much to bo said for tho modern trend; oil pumping when running " against compression " accounts for much of the tendency rapidly to carbonise. Employment of a free-wheel device lias helped to prove this fact in cases in which the mechanism has been in use for sufficiently long periods to justify tho expression of an , , . ... One of tho surprising facts is that engine braking on top goar has been accepted as> efficient for so long with very little question. The improvement of frictional braking has shown that tho faith of olden times is misplaced to-day. The engine with a heavy flywheel, such as the average compression-ignition unit, slows down gradually and acts against the brakes for a short period; this is sufficient to increase tha distance required to pull up from any required speed. From tests of free-wheel vehicles, or—in the case of conventional transmissions —by declutching at the time the brake is applied, it has been found that the retarding value of the engine, when top gear is in use, is an illusory hope, so far as a rapid stop is concerned. The statement by those opposed to free wheels that their use will cause many accidents due to the loss of the engine brake in traffic is groundless and actually opposed to facts. t