With each of the options, the vol/cap ratio Av of vehicle journey item v is calculated as follows:
Capacity v corresponds to the value of the attribute selected by the user for the seat capacity of a vehicle journey item. The pre-set default amounts across all vehicle journey sections, which service the vehicle journey item without regard to the calendar day. Thus the volume of a vehicle journey item sums up from the volumes of all connections using this item:
Path legs covered with PuT-Aux are not regarded for the vol/cap ratio-dependent impedance calculation.
Calculation from the assumed standing minutes (German Rail – (DB))
The assumed standing minutes (E) are the mean value of the time, a passenger expects to find no seat during his ride if passengers have random access to the seats on each stop-stop relation. The latter is due to the fact, that it cannot be distinguished between passengers who are already on board before the overloaded route section is reached and passengers who board in this route section. This interpretation of the standing minutes applies to the capacity of a vehicle journey item definition with regard to the number of seats. More generally, this is a discomfort which increases with the vol/cap ratio.
For a vehicle journey item v, the standing probability is approximated by a potentially asymptotical function:
The user has to set the parameters a and b, and Av is the vol/cap ratio.
The expected standing minutes of a connection V correspond to a volume-dependent impedance and result from adding the product of standing probability and run time across all vehicle journey items of the connection:
Using a penalty function for computation (Swiss Rail – (SBB))
The impedance of a vehicle journey item v is defined as follows:
The parameters a, b, c, l1 and l2 have to be entered by the user, Av is the vol/cap ratio of vehicle journey item v. Thereof, the parameters r, α, ß and γ result due to the function which can be constantly differentiated here l1 and here l2.
Thus, the impedance of a connection V is calculated as follows:
Using a linear penalty function for computation (Linear)
The impedance of a vehicle journey item v is defined as follows:
a and b are user-defined parameters, Av is the vol/cap ratio of a vehicle journey item v.
Thus, the impedance of a connection V is calculated as follows:
Calculation via DGITM – CGSP (France) function
In contrast to the other Vol/Cap ratio-dependent impedance calculations, this function distinguishes between two cases of impedance for a vehicle journey item v:
The quantity k_Seat is calculated as follows:
k_Seat = a + b * p
The quantity k_Stand is calculated as follows:
k_Stand = c + e * p
where p is the number of standing passengers per unit of area. You can set the unit for calculating surfaces in the network settings (Using Visum: Selecting a default setting for the system of units in the current network). p is calculated based on:
p = Number of standing passengers/number of standing places • maximum passenger density.
To calculate the number of standing places, you need to enter the total capacity and seat capacity. In addition, it is assumed that passengers only start standing once their volume exceeds the seat capacity.
a, b, c and e are parameters that must be entered by the user.
Thus, the impedance of a connection V is calculated as follows:
