Why are PTV_RestrictionZones not possioble in xDima?

[Bernd Welter]

Hi folks,

The documentation of xDima Operations mentions this:

Creates a distance matrix by calculating road distances and travel times between given locations. An InvalidValueFault is returned if the Feature Layer theme PTV_RestrictionZones is activated. PTV_RestrictionZones cannot be used for distance matrices. Returns a summary of this distance matrix calculation.

I've been asked for more info about why this feature layer is not supported in xDima. Maybe the following statements give more insight:

• HIGH_PERFORMANCE_ROUTING and PTV_RestrictionZones don't match because the "validity" state of a segment in the context of PTV_RestrictionZones may depend on the involved waypoint coordinates - which are not known at the time the HPR is calculated. So this is a conceptual topic.
• With CONVENTIONAL routing one has to understand that an [n:m] distance matrix is calculated through a partitioning approach:
  • If (n<m) we calculate "n matrices of [1:m] shape", otherwise we compute "m matrices of [n:1] shape".
  • We then assemble the result matrix internally.
  • That being said the state of a segment once again might not be "equal" for all waypoints.
  • This is not the same "conceptual" obstacle as in HPR, but the potential compensation of this would cause the performance to drop more or less to an inacceptable range (based on n*m elemental [1:1] routings).

Unfortunately the consequence is that there's no real workaround for this. Except for an extremely "hungry" Custom Feature Layer approach (not 100% correct result + high efforts = no fun).

Once again thanks to Max for the insights!

Bernd