ABSTRACT
The basis of such laws is quite simple: the faster you are travelling, the greater the risk of loss of control and collision, and the greater the level of injury. If you are intoxicated from some substance, the more intoxicated you are, the greater the chance of collision. Legal limits are established for acceptable levels of alcohol in blood, breath
or urine. Currently in Ireland, the primary legislation for dealing with all road traffic offences is the Road Traffic Acts 1968-2011 (and supporting statutory instruments). The legislation details the maximum legal limits, which are:
■■ Limits for experienced drivers • 50 milligrammes (mg) of alcohol per 100
millilitres (ml) of blood • 67mg of alcohol per 100ml of urine • 22 microgrammes (mcg) of alcohol per
100ml of breath ■■ Limits for professional drivers (bus/taxi/
haulage etc), learner drivers and inexperienced drivers who have been driving on a full licence for two years or less • 20mg of alcohol per 100ml of blood • 27mg of alcohol per 100ml of urine • 9mcg of alcohol per 100ml of breath
The assessment of the effects of drugs and alcohol on ability to drive (in addition to a simple legal limit) is very important because of the variable individual response to the effects of alcohol and other substances. In many cases, ‘driving under the influence’ may be confirmed by the ability, or failure, to pass standardized tests of sobriety, or by medical examination to determine whether the
ability to drive may be impaired, following preliminary impairment tests undertaken by Gardaí.
