Samenvatting
When a road safety study is contemplated one has establish how many accidents are needed to reach conclusions with a given level of confidence. Later, when the results are in, one has to be explicit about the confidence with which conclusions are stated. The purpose of this note is to describe a back-of-the envelop way of answering such questions with a precision that is sufficient for practical purposes. (A) Reprinted with permission from Elsevier.