PTV Visum - Frequently Asked Questions (FAQs)


Which settings are (generally) recommended for PrT assignments?

The following settings are recommended:
Assignment parameters:
- The number of iterations should be as high as possible. Using equilibrium_Lohse the number should be at least 100, even better 1000.

Functions (Calculate -> Procedure -> PrT functions):
- VDFs should be yet rising in the underload range, that means i.e. that for BPR the exponent should never be higher than 4, even better 2-3. In the overload range, a linear gain is desired (i.e. VDF 'Lohse').
- Scaling of impedance, i.e. Imp = 100 * tcur.
- Number of decimal places for PrT demand = 3 (until Visum 9.5).