The survey was provided nationwide, at the random sample of n = 1000, representatives of Poles aged 15 and over. Both the total sample and the created subgroups were based on demographic variables (gender, age, education, occupational status - working / not working, place of residence) and the fact of having or not having a driving license (driver / non-driver).

When analysing the results of individual groups (e.g. driver / non-driver, male / female etc.), it is important to know the size of these groups, because it involves a change in the size of statistical error (the smaller the sample size, the greater the error, hence rarely recorded statistical significance of differences within the obtained results), so all charts contain information about the size of each group.