This is the response of the ABD to the North Review of Drink and Drug Driving Law.
See for questions.
February 2010

Introduction and Summary

The ABD was formed in 1992 to campaign for a better deal for Britain’s motorists. It is a voluntary organisation funded by subscriptions and donations from its members and supporters. It receives no funds from public bodies or private-sector businesses, so is truly independent. The ABD is a member of the Parliamentary Advisory Council for Transport Safety and the National Council of Voluntary Organisations.
The ABD wishes to make the following general points before answering the numbered questions in the consultation.
On drugs:
The ABD recognises the difficulty of tackling drug driving, when there are so many substances involved and it may be hard to establish levels at which a driver becomes unfit to drive. Nevertheless, fair enforcement has to be based on impairment and the ABD would not support the creation of an absolute offence of driving with any trace of an illegal drug in the body, regardless of whether it affected a driver’s ability. It is right to discourage the use of illegal drugs, but driving penalties should not be used as a punishment for such use if no impairment can be established.
On drink:
The ABD supports the advice that drivers should not drink at all if they are planning to drive. Nevertheless, it would not support a reduction in the legal blood alcohol level, since there is little evidence that drivers with blood alcohol levels in the 50–80 mg range pose a significant risk. The greatest risk comes from drivers exceeding the current limit by a substantial margin, so better enforcement of the existing law would produce much greater safety dividends than reducing the limit.
A reduced limit would also result in an increase in morning-after convictions, when drivers might be slightly over the limit but show little sign of impairment. There is evidence that impairment is less for a given blood alcohol concentration when the level is falling than when it is rising. Punishing otherwise responsible individuals for minor exceedences of a lower limit in these circumstances could create resentment and undermine the current support for drink driving legislation.

Questions on drug driving

  1. The ABD accepts that drug driving is a more difficult problem to tackle than drink driving, since many substances, both legal and illegal, may be involved and taken singly or in combination. The existing law may be difficult to enforce, therefore, on the basis of subjective tests of impairment.
  2. The current law may not be enforced by the police as well as it might because of the difficulty of establishing impairment. Reductions in police traffic patrols, however, have almost certainly contributed to the rise in drug driving, as offenders believe they have little chance of being caught. The ABD believes the police have adequate powers to stop drivers they believe are impaired from whatever cause.
  3. Enforcement would clearly be easier if there were specific offences that prohibited driving while particular drugs were in the body at levels that could be shown to cause impairment, assuming reliable tests were available that could detect and measure levels of those drugs.
  4. (a) It would not be acceptable, in the interests of securing easy convictions, to introduce a law that made it an absolute offence to drive with any trace whatsoever of an illegal drug, if there was no evidence of actual or likely impairment at the measured blood level. Traces of some drugs, notably cannabis, can be detected long after any impairment effects have disappeared. While the use of illegal drugs should be discouraged, this worthy aim must not be pursued by punishing drivers who are not causing actual danger. (b) For the above reasons, it would be better to set specified maximum levels of drugs in the body before prosecution for a driving offence was brought, where scientific evidence on impairment is available to set such limits. The ABD does not have the expertise to suggest which drugs should be specified.
  5. Given the number of drugs, both legal and illegal, that could impair driving ability, the existing offence of driving while unfit should be retained.
  6. Any new offence(s) should specify only those drugs that, used inappropriately, will impair a driver’s ability, regardless of legality.
  7. Presumably this question is aimed at a situation where a driver has traces of both alcohol and one or more drugs, but levels of each are below the prescribed limits. It would be impracticable to legislate for every possible combination, so the existing law would need to be used in such cases.
  8. Some police forces already test all drivers for alcohol if they are involved in a road accident. The same discretion should be allowed for drug testing without the need for legal compulsion.
  9. to 12. The ABD is not in a position to answer these questions.

Questions on drink driving

  1. The ABD believes that the current limit of 80 mg of alcohol per 100 ml of blood is the best compromise between deterring irresponsible behaviour and unnecessarily penalising drivers who present a very low risk. The ABD does not condone drinking and driving, and supports the advice that ideally drivers should not drink at all if they plan to drive. The ABD opposes a reduction in the legal limit, however, partly because it would cause more responsible drivers to fall into the morning-after trap. The current limit also has widespread support, with little sympathy for those caught in excess of it. This could change if the limit were reduced.
    In November 2008 the Department for Transport published a consultation on road safety compliance, which included a section on drink driving. Table 3.2 of the consultation paper showed that just 1 per cent of drivers and riders killed in road accidents had a blood-alcohol concentration (BAC) in the range 50–80 mg. The figure was 2 per cent in the range 80–100 mg and rose substantially at higher levels. The fact that a driver had some alcohol in their system does not necessarily mean that this was the cause of their accident, since they could have been the innocent victim of another road user’s error or bad driving. There is almost always more than one contributory factor in any accident.
    In February 1998 the former Department of the Environment, Transport and the Regions (DETR) published a consultation document on combating drink driving. In Annex 1 to that consultation, reference was made to roadside surveys conducted at various sites around Britain between 1988 and 1990. These showed that 2.3 per cent of drivers tested (i.e. a sample of all drivers, not just those suspected of drinking) had a BAC in the 40–80 mg range. Reference was also made to a study of road accident victims attending the John Radcliffe Hospital, Oxford, during the same period. This showed that 2.1 per cent of drivers had a BAC in the 50–80 mg range. These figures suggest that the proportion of drivers involved in accidents with a BAC level between 50 and 80 mg is much the same as that of the driving population as a whole, indicating that there is no perceptible increase in risk at this BAC level.
    Since Table 3.2 shows rapidly growing percentages of drivers killed as BAC levels exceed 100 mg, there can be little doubt that alcohol is more likely to be the main contributory factor as BAC levels rise. The figures given in the earlier DETR consultation suggest there would be a negligible impact on accidents if the limit were reduced to 50 mg. The main problem is clearly caused by those who exceed the current limit by a substantial margin, so this is where enforcement should be targeted.
    A lower limit would make more drivers vulnerable to the morning-after trap, when they may have avoided driving while drinking the night before but still be over the limit the following day. There is evidence that, for a given BAC, a driver is more impaired when the level is rising than when it is falling. The following comes from Loosening the Grip: A handbook of alcohol information by Kinney and Leaton (ISBN 0-8016-2769-9, page 42 in the 1991 edition):
    The neurophysiological basis for intoxication is not fully understood, but the intensity of the effect is directly related to the concentration of alcohol in the blood, and hence the brain. The degree of intoxication is also dependent on whether the blood alcohol level is rising, falling, or constant. It is known that the central nervous system and behavioural effects of a given blood alcohol concentration (BAC) are greater when it is rising. This is called the Mellanby effect. It is as if there were a small “practice effect” or short-term adaptation by the nervous system to alcohol’s presence. Thus for a given blood alcohol level, there is more impairment if the blood level is rising than is found with the same BAC when the level of alcohol in the blood is falling.
    Consequently, a driver might feel, and be, safe to drive the next morning while still having an illegal level of alcohol in their blood. Drivers prosecuted for having a BAC in the 50–80 mg range in these circumstances might feel they have been treated unjustly, and this could weaken support for the drink-driving laws. While no fixed limit for BAC can ever exactly match the level at which significant impairment begins in different individuals, the current limit has the virtue of being based on a large-scale study in the 1960s and is generally accepted as reasonable. This is important and the current limit should not be reduced unless strong evidence emerges that a lower limit would prevent a significant number of accidents. No such evidence appears to exist at present.
  2. The ABD considers that the current penalty regime for drink driving offences is sufficient, although a more flexible system might be beneficial (see answers to Questions 7 and 13).
  3. The Department for Transport’s compliance consultation put forward three options for tightening procedures before high risk offenders (HROs) are allowed back on the road at the end of their disqualification period. One that the ABD would support is to implement the powers provided by the Road Safety Act 2006, to require HROs to prove their fitness to drive before a ban expires. This support is conditional on procedures being in place to give HROs ample time to submit the medical evidence required.
  4. The greatest deterrent to drink driving is the perceived likelihood of being caught. As with drug driving, reductions in police traffic patrols have led to the belief by some offenders that they are less likely to be apprehended.
  5. A greater police presence on the roads would act as a deterrent, which is more important than detecting offences once they are committed. The ABD believes the police have adequate powers to stop anyone they suspect of drink driving, so there is no need for a specific power to carry out random testing. Indeed, if random testing were allowed, it is likely that police resources would be wasted in carrying out tests on innocent drivers when they should be targeting those showing clear signs of impairment.
  6. The Government’s message on drink driving quite clearly sets out the potential consequences, both in terms of accident risk and legal sanction. The message with drug driving is perhaps less clear, especially with regard to legality.
  7. If the blood alcohol limit were reduced, which the ABD hopes will not happen, it would certainly be necessary to impose a lower penalty for drivers in the 50–80 mg range. Removal of the mandatory driving ban would be essential to avoid unduly harsh penalties for those representing very little risk.
  8. If the general blood alcohol limit is set at a level where drivers pose little if any additional danger compared with those who have not drunk at all, there should be no need for lower limits for certain classes of drivers.
  9. On the basis of innocent until proven guilty, a person’s driving licence should not be suspended if they fail a breath test. An exception could be justified in the case of someone with a previous conviction for drink driving, indicating that they could pose a particular risk.
  10. If new breath testing equipment can be guaranteed to provide a sufficient level of accuracy, the ABD would not object in principle to withdrawing the right to a blood or urine test. There would need to be adequate safeguards, however, against unjust convictions on the basis of a single breath test, especially in the case of blood alcohol levels marginally above the limit. If a breath test is taken shortly after a driver has finished drinking, the breath alcohol concentration may not be an accurate indicator of the blood alcohol level. It is suggested, therefore, that two breath tests should always be required, the second one to be conducted not less than 20 minutes after the first, and both must show a reading in excess of the limit for a driver to be charged.
  11. The ABD is not aware of any legal or procedural barriers to enforcing the current law.
  12. As already pointed out in response to Question 1, the ABD believes that a reduction in the current blood alcohol limit would have a negligible effect on casualties. It would be likely, however, to lead to more convictions of responsible individuals caught in the morning-after trap, which would cause resentment and bring the law into disrepute. The wider implications would most probably include an accelerated rate of closure of public houses in rural areas, with detrimental economic and social consequences for those communities. Paradoxically, rather than reduce drinking overall, a lower limit could cause more people to stay at home and drink cheap alcohol from supermarkets rather than drink responsibly in the more controlled environment of public houses.
  13. Some other countries operate a sliding scale of penalties according to the degree to which a driver exceeds the legal alcohol limit. This more flexible approach would be beneficial in the UK, especially if the blood alcohol limit were lowered. It is right that extreme offenders should be treated severely, but those posing little risk should face lower penalties.


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