Undoubtedly this has meant that some drug users have escaped and that there have been more accidents than there might have been. New road-side devices to be tested by four police forces, including Strathclyde, should remedy that situation. Nevertheless, it is open to question whether this should mean an increase in random testing. The legal position affecting drugs and alcohol is different. It is not against the law to use or possess alcohol, only to attempt to drive with too much of it in one's bloodstream.
Drugs falling within defined classifications, in contrast, are simply illegal.
Equally, traces of drugs such as cannabis stay in the bloodstream for much longer than alcohol. Thus it is possible that random tests will catch out someone who is driving perfectly well but who may have smoked cannabis a fortnight previously. In other words, a road safety campaign will become confused, to say the least, with action against drugs. Parameters must be set for the police, in other words. Safe motoring, not the general problem of drug use, should be their immediate concern on the roads.