The method sums the amount of time required to serve all movements at saturation for a given cycle length and divides by that reference cycle length. This method is similar to taking a sum of critical volume to saturation flow ratios (v/s), yet allows minimum timings to be considered. The ICU method uses the Level of Service concept, in which reports on the amount of reserved capacity or capacity deficit. In order to calculate the Level of Service for the ICU method, the ICU for an intersection must be computed first. ICU can be computed by: