SECTIONAL TRANSACTIONS .—G. 419 
from the point of view of structural failure, and some erroneous views 
regarding the function of the tread in this respect are corrected. 
Practical Demonstration —Several of the points referred to in the paper 
were illustrated by skidding tests carried out on two cars. 
These were designed to show : 
(a) The difference between new and worn tyres in their effect on 
braking a car on a wet surface (brakes correctly adjusted). 
(b) The difference between stopping distances on two different types 
of wet road surface (on worn tyres). 
(c) The effect of a small variation in speed on cornering ability. 
(d) The effect of badly adjusted brakes on the behaviour of a car in an 
emergency stop. 
Dr. C. S. Myers, C.B.E., F.R.S—The psychological approach to the 
problems of road accidents. 
The psychologist’s approach to the problems of road accidents is broader 
than that of most other experts—statisticians and engineers, for example— 
who are concerned with the same problems, since he must study all the 
factors which react upon road users and may therefore have some influence 
on accidents. He is not content, for example, with mechanical perfection 
in car controls ; but he would institute an enquiry into which forms and 
positions of controls best satisfy the human requirements of the driver. A 
similar study is required of traffic signals and of road lighting systems. The 
psychologist holds that there is need for a thorough investigation of the 
combined total effect of traffic regulations, for he realises that there is a 
danger of their becoming so numerous that an excessive strain is imposed 
on a driver’s attention—a strain that may easily enhance his liability to 
accident. 
A further line of enquiry is into the values of incentives and deterrents 
in promoting good road behaviour. The industrial psychologist’s experi- 
ence with these problems in other spheres will be valuable to him here. 
The technique which he has evolved for market researches, and especially 
for those researches which relate to the use of advertisements, would be 
particularly useful in exploring methods of propaganda for road safety. 
In studying accidents, the psychologist will take into account the remote 
as well as the direct causes—the effects of predisposing previous strain, 
fatigue, worry and irritation. He must further be in a position to recognise 
the mental and physical abilities and the qualities required for a safe driver, 
to assess them, and to discover whether a driver possesses them in adequate 
measure for him with fair safety to follow his unquestionably dangerous 
occupation or amusement. Experiments on tests which will enable him 
to do this have been conducted by the Industrial Health Research Board, 
which has sought for a means of detecting the ‘ accident-prone,’ whether 
engaged in industrial occupations or in driving. A battery of tests has 
been prepared by the National Institute of Industrial Psychology specifically 
for motor-drivers, and results obtained with them show that while they 
cannot, of course, pretend that a driver who passes them satisfactorily will 
never be prone to reckless conduct, yet they can claim to select those drivers 
who possess the necessary abilities to extricate themselves from a dangerous 
situation when it confronts them. The use of similar tests in the Paris 
omnibus service reduced the number of accidents to these vehicles by 66 
per cent. during the period 1929-33, although the number of omnibuses 
increased by 77 per cent., and their speed limit by 44.5 per cent. During 
