Professional truck drivers suffering from obstructive sleep apnoea syndrome (OSAS) are more often involved in traffic accidents. OSAS can be treated successfully and the effects of treatment are visible almost immediately. Treatment of OSAS has shown a significant reduction in the number of traffic accidents. Based on criteria for effective treatment, the requirements for the ability to drive have recently been modified by ministerial decree. The period during which persons with OSAS were not allowed to drive was formerly at least 1 year for a passenger car and 5 years for a truck or bus. The period has now been reduced to 2 and 3 months respectively. Legislation has also been adjusted for drivers with narcolepsy and idiopathic hypersomnia for whom the use of psychostimulant drugs is allowed. The modified legislation is intended to prevent underdiagnosis, may improve driving safety and is in the public interest.