The purpose of the validation study is to develop a valid test battery for assessing driving ability in a driving simulator when influenced by drugs. Ethanol has known, well-documented and well-characterized effects on driving behaviour and accident risk, and will be used to assess the simulator test scenarios' sensitivity to drug effects. Once the test scenarios have been refined and their ability to predict driving accident risk have been validated, we plan to use the simulator to assess driving ability under the influence of different drugs suspected to produce driving impairment.

Inclusion Criteria:

• Healthy, caucasian males aged 25-50 years in possession of a valid driver's license for the last 5 years.
• Recreational alcohol drinkers without alcohol dependence or abuse, no traffic-related convictions or alcohol-influenced behavioural disturbances.
• 1 or 0 points on the modified Apfel scale for predicting post-operative nausea/vomiting (non-smoker, previously experienced nausea/vomiting post-operatively, previously experienced motion sickness)

Exclusion Criteria:

• Females (risk of teratogenicity)
• Non-caucasian ethnicity (possibility of deviant ethanol metabolism)
• Previous strong reactions such as nausea, fainting etc. during blood sampling
• Previous abnormal reactions to ethanol
• Previous convictions related to drug intoxication
• Previous excessive drug use
• Regular use of prescription drugs
• Two points or more according to the modified Apfel criteria