PTV Visum - Frequently Asked Questions (FAQs)

(#VIS12676)

Which methods are offered for matrix correction and for updating of existing demand matrices and which differences do they have?

Basically, the following methods are available:
1) TFlowFuzzy:
- To adjust a given OD matrix in such a way that the result of the assignment closely matches the observed link volumes or origin/destination travel demand:
- For PrT and PuT.
- For Link volumes.
- For OD travel demand by zone.
- For Turn volumes at nodes.
- For Any combination of these three.
- Counts and tolerances.
- Use of user defined attributes.

2) Matrix calibration:
- Calibration procedure according to Lohse.
- Only counts, no tolerances.
- Only AddValues, no user defined attributes.

3) Projecting PrT Path Volumes:
- Adjusts the OD-matrix of a certain PrT Demand segment to count data of certain manually choosen links.
- Only counts, no tolerances.
- Only AddValues, no user defined attributes.