Guest Blog by George Matthews
Drink driving law is relatively clear cut as to what constitutes being “over the limit”. A limit of 35 micrograms of alcohol in 100ml of breath is the legal breath limit and if you provide a breath sample above that level you are over the limit. Simple. Proof of any kind of "impairment" is unnecessary. Alcohol affects everybody differently and factors such as height and weight can affect the rate at which alcohol is eliminated from the body. The prescribed alcohol limit is therefore, to a certain extent, an arbitrary one. In a lot of European countries the limit is about half of that in the UK, and some countries even go as far as to have a zero tolerance policy on drinking and driving.
The law surrounding drug driving, however, is not as clear cut. There are no prescribed limits, which is in part due to the (ever-expanding) range of legal and illegal drugs. In addition to having to prove the presence of the drug in your system, normally achieved by way of a blood test and/or an admission of having taken the drug, the prosecution must prove that your driving has been impaired as a result of that drug.
As the technology stands, most drink drive cases are disposed of by way of breath samples being taken on a breathalyzer machine at a police station with the results of the breath analysis being near-instantaneous. Stopping someone for drug driving, however, usually involves doing impairment tests at the roadside, examination by a doctor at a police station, the taking of blood and the analyzing of blood which can take weeks. These more onerous steps could account for the significantly lower number of people being stopped for, and being convicted of, drug driving. The external signs of drug use can also be more subtle than those of alcohol which could also be a reason for the lower detection rate.
There has been increasing publicity surrounding the committee of experts set up by the Department for Transport to investigate the possibility of introducing prescribed limits for drugs. These limits would be very similar to that currently in place for alcohol.
Whilst any move to introduce laws to make our roads safer can only be a good thing, these limits, if set, will need to be considered very carefully. Just as with alcohol, these limits will necessarily be arbitrary to a certain extent. There would clearly be a great injustice if you committed a driving offence, which would probably punishable with a mandatory ban, by taking a couple of paracetamol tablets before getting behind the wheel.