This workpackage considers the effects of using alcohol, drugs and medicines on driver impairment and traffic accidents. The workplan includes a combination of epidemiological and experimental methods to provide the basis to calculate accident risk and 'tolerance levels' with reference available data on fatal and injury accidents related to alcohol, drugs and medicines.
Table 7. Summary Description of Research Workpackage for Alcohol, Drugs and Medicines.
Objectives This WP deals with the IMMORTAL objectives related to impairment, accident risk and assessment methods based on ‘tolerance levels’ for drivers with acute impairment related to consumption of alcohol, drugs or medicines. Description of work / tasks Review Task R4.1: Review of knowledge, including analysis of information in existing databases on drugged drivers, e.g. performance data, personality assessment, driver record, psychological and medical judgement and reporting (month 1-6). Survey/Epidemiological Studies Task R4.2: Epidemiological research in three countries aimed at assessing the relative accident risk of drivers impaired by drugs or medicines, alone or in combination with alcohol. Random roadside tests of drivers and blood samples taken from accident injured drivers at the same places and times of the day as the road side tests will serve as basis for the research (month 1-27).
Task R4.3: A qualitative analysis of accident causal factors related to impaired drivers, by means of anonymous in-depth interviews of the parties in such accidents, carried out in co-operation with physicians at selected hospitals (month 1-28). Experiments on recreational drugs Task R4.4b: Experiments on driving performance and risk taking by persons impaired by amphetamines and ecstasy, alone or in combination with alcohol. Both cognitive tests and driving tests in an instrumented car in relation to different doses of impairment will be carried out in order to suggest tolerance levels (month 1-28). Experiments on medicinal drugs Task R4.4d: Experiments on the effects of flu medications on driving performance and cognitive functioning in combination with fatigue (sleep deprivation). Fatigued subjects diagnosed with the flu will be compared to with and without medication, and to baseline conditions. Impairment will be measured by psychometric tests and driving performance in a simulator to examine implications for accident risk (month 1-28).
Evaluation Task R4.5a: Roadside impairment testing of drivers stopped at the roadside in close co-operation with the roadside survey in Task R4.2 (month 1-28). Management Task R4.6: Workpackage management and reporting (month 1-36) Deliverables D-R4.1: Review of impairment and accident risk for alcohol, drugs and medicines. D-R4.2: Survey and epidemiological evidence of impairment and accident risk for alcohol, drugs and medicines. D-R4.3: Qualitative analysis of accident causation from alcohol, drugs and medicines. D-R4.4: Driver impairment, accident risk and tolerance levels from consumption of drugs and remedy medicines. D-R4.6: Alcohol, drugs and medicines: A synthesis of results. Milestones (and criteria)
Month 6: Completion of Deliverable D-R4.1
Month 28: Completion of Deliverable D-R4.2, D-R4.3, D-R4.4
Month 30: Completion of Deliverable D-R4.6
(QA authorisation) Interrelation with other workpackages and expected results Specific relation to other workpackages include acute impairment due to consumption of drugs and medicines related to ageing, illness and diseases (R1) and assessment method policy (P). The results of this workpackage will identify the type of impairment and presumed level of accident risk associated with types of acute impairment from alcohol, drugs and medicines.
As the problem of alcohol in traffic has decreased over the last 10-15 years the present international situation is characterised by an increasing concern about drugs and driving and by various attempts to elucidate and intervene against this problem. It is recognised that drugs, even more than alcohol, is a complex issue. It is also recognised that drugs in combination with alcohol form an even greater problem because the combination will often result in a synergistic effect.
In spite of national differences, international literature indicates that licit and illicit drugs, often combined with alcohol, are increasingly found in dead and injured road users, e.g. in 10-20% of killed drivers (of motor vehicles, including cyclists) and often in combination with illegal alcohol concentrations. However, when it comes to describing the extent of the drug-driving problem, great uncertainty prevails, as experiments, roadside surveys and accident statistics are sparse and inadequate. For example, there are few valid baseline indications of drugs in non-accident cases from which to calculate accident risk and 'tolerance levels' relative to other 'standards' such as alcohol (BAC limits) or fatigue.
Only two major roadside surveys have been identified, one from Australia , the other from Germany . Both studies were based on saliva samples and indicate similar results for passenger car drivers. About 1% had taken illicit drugs primarily cannabis/stimulants and about 4-6% had taken licit drugs, primarily stimulants, hypnotic or anxiolytic drugs, or drugs without impairing effect.
Recently a smaller study was carried out in the Netherlands . The voluntary tests were based on urine samples and indicated that 1% was positive for medicines and 5% for illicit drugs, mostly cannabis. These results are reverse to the first mentioned.
It is crucial to get more precise information on drugged driving in order to be able to change the law towards giving the police legal rights to conduct random tests for drugs in traffic. Moreover, better devices for screening at the roadside have been developed during recent years, which means that we will be able to produce more exact knowledge about the problem of drugged driving.
In some countries another approach to reveal the size of the problem has been taken. In Australia1, Belgium , Spain and Sweden drivers have been interviewed at rest areas or emergency rooms about their drug use. Results indicate that 5-10% of the drivers admit use of drugs "hazardous" to road safety, primarily benzodiazepines and 3-5% admit use of illicit drugs, primarily cannabis or amphetamines. It would be interesting to get information on driving habits in connection to drug use by drivers who were found positive at random road side tests.
Despite the fact that calculations of accident risks are subject to great uncertainties, this has been done for example in Australia . These calculations indicate that the relative risk of being killed in a fatal accident is significantly increased for drug-impaired drivers compared to drug-free drivers, especially for drivers impaired both by drugs and alcohol.
In addition to common drugs and medicines such as cannabis and ecstasy (amphetamines). Some results indicate that the risk of accident involvement is restricted to the first 2-3 weeks after start of a treatment, while others show that this is also the case for longer periods. More research is required to ascertain the effects of these drugs and medicines on driver impairment and accident risk. Such research should include the recommendation of 'tolerance levels' that may be applied to roadside methods of impairment testing.
This workpackage is led by DTF. This workpackage explores drivers' impairment of the most common drugs and medicines in relation to traffic safety in the following respects:
relative accident risk associated with impairment of driving performance;
nature of the impairment and its relation to driving performance and risk taking;
accident causal factors related to impairment;
test of the usability of various methods and devices in the laboratory and at the road side to assess drivers' impairment.
Review
Task R4.1 Review of knowledge, including analysing existing databases of impaired drivers in relation to performance data, personality assessment, driver record and psychological and medical judgement. KUSS will carry out the task, including a review in order to decide upon variables to be analysed.
Survey and Epidemiological Studies
Task R4.2 Epidemiological research aimed at assessing the relative accident risk of drivers using drugs and medicines, alone or in combination with alcohol, by means of roadside surveys and blood samples from accident injured drivers. Analyses of blood samples from accident injured drivers will be compared with screening results from a random sample of drivers at the roadside. Each of the involved partners will conduct tests of a total of 1500-2000 drivers for prevalence of benzodiazepines, opiates, amphetamine, cannabis, cocaine, ecstasy and alcohol by means of saliva or urine tests. In co-operation with the police, drivers will be stopped at randomly selected sites and times. Samples from injury involved drivers in the same period and geographical area would be sought at hospitals and tested for the same substances. The tests will be carried out by means of saliva or urine, in total from 750-2000 injured persons by each of the involved partners, followed by blood samples from drivers who showed a positive reaction. The data will be used to estimate the accident risk of impaired drivers. Methods for tests of saliva will be chosen in close co-operation with the results from existing projects (e.g., ROSITA) and will include such candidate devices as. Cozart rapiscan, Syva rapid test, whereas the urine samples will be screened by EMIT II®, and positive samples confirmed by means of GC-MS. The task will form an important contribution to risk studies in terms of providing baseline data on the level of impairment in the general driving population, serve as input for risk calculations based on former published epidemiological studies and provide risk estimates based on driver injury data. Furthermore, the task will examine the practicability of the techniques for routine use. Three partners will carry out studies: SWOV, TRL and TOI. The task will include pilot tests, establishment of contact to legal authorities, police, hospitals and analytical laboratories, decision on test equipment and plan for the road side tests, blood samples from drivers in traffic injuries and data analysis. TOI will be responsible for the co-operation between the three involved partners and for the joint report.
Task R4.3 A qualitative analysis of causal accident factors related to impaired drivers. DTF will carry out a prospective survey with the aim of providing information on accident causation factors related to impaired drivers. Drivers, who were brought to a hospital after a traffic accident, will be tested for impairment, and relevant persons will be contacted for an anonymous in-depth interview about the course of the accident. Police reports will be required to support the analysis. A total of 50 in-depth interviews are expected. The task will include a pilot study making contacts to selected hospitals, elaborating an interview guide in co-operation with physicians and testing the method, in-depth interviews of accident involved impaired drivers at hospitals and a qualitative analysis.
Experiments
Task R4.4 Experiments on driving performance by drivers impaired by selected drugs and medicines, i.e. amphetamines and ecstasy and by drivers who take flu remedy medicines, alone or in combination with alcohol. Both cognitive tests and driving tests will be carried out. Methods for cognitive tests will be chosen from consultation with recommendations for roadside impairment tests from related projects (e.g., CERTIFIED). Standard tests batteries with established validity and norms will be used. The test persons will be chosen from patient populations and the tests will include results related to different age groups and doses and a standard set of measures will be used for comparability between the studies. The task will suggest tolerance levels for the studied drugs and medicines in relation to driving performance. Three partners will carry out studies:, UM-BBI and UNIV LEEDS. The task will include a pilot study on tests, recruitment of test population, decision and set up of test methods, data collection and data analysis. UM-BBI will be responsible for the co-operation between the four involved partners and for the joint report.
Evaluations
Task R4.5a Road side impairment testing of drivers stopped at the road side in close co-operation with the road side survey in Task R4.2. A number of 200 drivers who are stopped in the road side survey will be further examined for impairment. Methods for cognitive tests will be chosen from consultation with recommendations for roadside impairment tests from related projects (e.g., CERTIFIED). SWOV will use standardised test batteries with established validity and norms.
Management
Task R4.6 Work package management and quality assurance. The work package leader (DTF) will manage the tasks in co-operation with the task leaders and assure the quality of the work. DTF will be responsible for the co-operation between all partners involved in R1 and for the joint synthesis report The results of the various studies will be linked and recommendations for further action will be proposed in the report, including suggestions for 'tolerance levels' applicable to licensing assessment.
