With the co-operation of a further 13 institutes and as a continuation of our own epidemiological-statistical survey, we recorded the total and relative distribution (frequency profile) of the blood alcohol concentration of car drivers for the 3rd quarter 1990 and the 1st quarter 1991. The participating institutes recorded almost 27,000 blood samples and compared them with results of the first part of the study (1989). The survey dealt separately with sex-, age- and time of day-distribution of drivers involved and not involved in road accidents. One of our repeatedly presented field research into the problem of "alcohol and road safety", once again, provided to be a useful method in the run-up to the unprejudiced alcohol test which we are striving for. We noticed characteristic changes in the frequency profiles of the old and the new counties (Bundesländer) in Germany in the 1st (1989) and the 2nd (1990/91) report of the study. The results of Police supervisory operations in the administrative district of Cologne have basically given useful indications as to their epidemiological-statistical value as evidence.