Using headway-based or timetable-based assignment you cannot only calculate skims for the assignment period, but also calculate skims for analysis time intervals. The program then accounts for analysis time intervals that overlap with the assignment period.
Decisive for the assignment to a time interval is the demand it contains. The search for connections is carried out jointly for the entire assignment time period and for the post-assignment time period. The choice is calculated per demand interval, so it is not the analysis time intervals that are included, but the intervals defined by the demand time series. This means that for skims of the analysis time interval, connections outside the time interval are also taken into account if they are used by the demand of this time interval. The skim for each analysis time interval is calculated from the shares of the demand time intervals.
Example: An analysis time interval is defined from 8 AM to 11 AM. There are two demand time intervals from 7 AM to 10 AM and from 10 AM to 12 AM. Two thirds of the skims are derived from the first demand time interval and one third from the second.
The skim is assigned the value for "no connection found" if no path was found in the entire assignment time period. If a connection is used outside a demand time interval, this is indicated by the "adaptation time” skim.
In addition to the restrictions for skim calculation listed in Table 170, the skims discomfort and service frequency are also not calculated.
