Science speaks...
1927
Tests for drunkenness
Deplored the term 'drunk' and recommended the following definition 'a person who is so much under the influence of alcohol as to have lost control of his faculties ..... to such an extent as to render him unable to execute safely the occupation on which he was engaged at the material time'.
1935, 1960 and 1965
Relation of alcohol to road accidents
The report challenged the estimate given by the Ministry of Transport in 1933 that only 29 out of 3,297 fatal accidents involving motor vehicles were caused by alcohol or other drugs. The Report observed that this 'took no cognizance of those persons who had been under the influence of alcohol to such an extent insufficient to attract notice'.
The BMA's two other reports stated:
' a concentration of 50 mg. of alcohol in 100 ml. of blood while driving a motor vehicle is the highest that can be accepted as entirely consistent with the safety of other road users. While there may be circumstances in which individual driving ability will not depreciate significantly by the time this level is reached, the committee is impressed by the rapidity with which deterioration occurs at blood levels in excess of 100 mg./100ml. This is true even in the caseof hardened drinkers and experienced drivers. The committee cannot conceive of any circumstances in which it could be considered safe for a person to drive a motor vehicle on the public roads with an amount of alcohol in the blood greater than 150 mg./100 ml.'
1958
The Risk Taken in Driving under the Influence of Alcohol
Professor John Cohen of Manchester University carried out a series of tests on three groups of Manchester bus drivers. The first group was a control group of sober drivers; the second had been given two single whiskies and the last group were given six single whiskies. The amounts of whisky were equivalent to almost one pint of beer and 2.25 pints respectively.
Cohen discovered that even sober drivers made grave errors of judgement. Errors grew at blood alcohol levels below 50mg and several drivers were confident of their ability to drive an 8ft wide bus between posts less than 8ft apart! The third group became excessively over confident - they believed they could do better!
1959
Medical Research Council report 'Effects of Small Doses of Alcohol on a Skill Resembling Driving'
Professor G C Drew tested drivers on a driving simulator and found that "wobble" across the road increased as soon as alcohol was in the blood. Relation between error and blood alcohol was a straight line, proportional increases in blood alcohol produced proportional increases in error, an average of 16% increase in error at 80 mg.
The report concluded that alcohol has 'no threshold, behaviour begins to deteriorate as soon as there is any alcohol in the blood'.
1962
Borkenstein's Grand Rapids Study
In 1962 in Grand Rapids, United States of America, a detailed survey was carried out which covered accidents over a full year. After interviewing thousands of drivers who had or had not been involved in accidents, 622 accidents were selected in which no other vehicle was involved in order to establish the relationship of the amount of alcohol in the blood with traffic accidents.
When the blood alcohol level went up from 10 mg. to 50 mg. accident proneness increased 50%; when it reached 60 mg. accidents were doubled; at 80 mg. accidents had quadrupled; at 100 mg. accidents had increased sevenfold; and at 150 mg. accidents had increased twenty five times.
