The performed trials were supposed to answer the question, which level of alcoholisation causes 'absolute impairment' of riding a bicycle. In particular, the authors wanted to find out if the valid threshold value of 1.6 g/L blood alcohol level (BAL) needs adaptation. Therefore they carried out drinking cycling trials under conditions as realistic as possible (e.g. asphalt ground, different weather conditions, alcohol consumption in convivial gatherings). The trials performed by Schewe et al. served as a basis and were additionally expanded by new challenges and medical examinations. A total of 74 test persons of both sexes, aged between 18 and 53 years, participated in the trials. 83 evaluable test series were obtained. The trials were pre-approved by the ethics commitee of the Heinrich-Heine-University, Duesseldorf. Practical trials were conducted under special safety conditions, such as wearing a bicycle helmet and motorcycle protection clothing. The practical trials were videotaped. The inspection of the videotapes allowed an evaluation by allocation of failure points for certain distinctive features. From a medicolegal point of view it has to be underlined that relevant alcohol-related deficits can already be found at rather low blood alcohol levels (BAL). Most test persons were able to compensate the most severe alcohol-related deficits up to BAL of around 0.8 g/L and avoid severe mistakes during cycling. However the amplitude of fusion as determined during ophthalmologic examinationwas resistent to compensation mechanisms and decreased with increasing BAL. At BAL of 1.1 g/L alcohol-related deficits and resultant signs of an impairment to drive increased exponentially. Only isolated test persons were able to compensate alcohol-related deficits during the parcours at very high BAL. Up to 1.6 g/L BAL, some individuals made not more severe cycling mistakes than the median value for all participants under sober conditions. However, at 1.4 g/L BAL, at latest, no one was able to reach his personal cycling performance that he had shown when sober. (Author/publisher)
Samenvatting