Abstract
Different concepts for designing hourly volumes of traffic are discussed. It is shown that a frequency curve of hourly volumes over a year on a certain point can be obtained by the addition of an exponential curve and a normal curve. A parameter-free method-modal method- for the determination of an upper percentile point (e.g. the 70th) of the frequency curve of hourly volumes over a year has been worked out. Further, a cluster method of sampling is described, which requires a greatly reduced number of observations to test the calculation.