420 SECTIONAL TRANSACTIONS .—G. 
the same period the number of accidents to all motor vehicles in Paris 
increased by 5 per cent. 
It may be argued that the use of these tests may result occasionally in the 
exclusion of good drivers, and thus in some individual hardship. But 
surely it is better to do this than to admit those whose unsuitability will 
result in injury or killing their fellow-citizens. Even if this be not con- 
ceded, the tests might usefully be given to those whose conduct has resulted 
in threatened or actual accidents, especially as the tests reveal, from time 
to time, deficiencies in drivers which can be remedied by special training. 
Finally, the psychologist insists on the importance of systematic training 
for all road users. 
Mr. E. FarmMer.—Accident proneness among motor drivers. 
Statistical methods are available for determining from the recorded 
accidents of a group of individuals exposed to similar risks to what extent 
their accidents are mainly due to specially prone individuals. It has been 
found from all the accident records so far examined by this method that the 
accidents of any group of individuals are mainly due to a very small number 
of specially prone persons. If these few specially prone persons are elimi- 
nated, the subsequent accident rate of the group is considerably reduced. 
It has also been shown of these specially accident prone individuals : 
(1) That they sustain an undue number of accidents in different 
periods of exposure. 
(2) That they sustain an undue number of accidents of different 
kinds, both blameless and blameworthy. 
(3) That they sustain an undue number of both minor and major 
accidents. : 
This means that accident proneness is a relatively stable individual quality 
that will manifest itself whenever the opportunity is given. 
Accident prone individuals can be detected by (1) psychological or other 
tests, (2) by examining their previous accident records. The former 
method is not yet sufficiently reliable for general use. The second method 
is reliable if means can be found for making it effective. 
The motor accidents recorded by the insurance companies could be 
examined to see how far it is possible from previous records to prognosticate 
an individual’s accident proneness. ‘This has already been done for a few 
thousand drivers and positive results obtained. Before any definite con- 
clusion can be drawn it is necessary to examine the validity of the hypothesis 
over a wider field, embracing every possible class of driver. Government 
co-operation would be necessary to do this. It is suggested that before 
licences were renewed a certificate from the applicant’s insurers should be 
produced giving his accident record for the previous period. If this plan 
were put into operation for a few years it would be possible to see what 
practical measures could be taken to lessen the number of accident prone 
drivers. 
AFTERNOON. 
Demonstration of skidding (2.0). 
Wednesday, September 11. 
COMMITTEE REPORTS AND DISCUSSIONS (10.0). 
Wing-Commander T. R. Cave BRowNE Cave, C.B.E.—WNotse (10.0). 
