Scientific opinions differ whether the use of stimulants causes deterioration in driving skills. In 1,857 of 8,709 cases of driving under the influence of drugs, amphetamine-like drugs (amphetamine, methamphetamine, and methylendioxyamphetamine) were present either alone or together with other licit or illicit drugs. In 338 cases, amphetamines were the only psychoactive substance group in plasma at mean, median, and highest concentrations of 0.18, 0.12, and 1.05 mg/L, respectively. A widespread opinion is that after the consumption of amphetamines, centrally stimulating effects with corresponding consequences on safe driving are expected. In contrast, many cases were observed that rather suggested an influence of centrally sedating substances when considering the psycho-physical conditions. Relations between concentration and effect could not be established. The apparent sedation is probably the consequence of sleep deprivation during an amphetamine binge and the after-effects of the drug. Abstract published by arrangement with John Wiley & Sons.