Service Area: split, dissolve differ using one facility

[Mer-lin]

Hi,

why is the network analyst producing different results when calculating the service area in overlap or dissolve compared to split mode (all high precision) using only one facility and the same network data?

See the screenshots for illustration.

Cheers,
Merlin

[MelindaMorang · Accepted solution]

The Service Area polygon generation algorithm for split polygons is different from the polygon generation algorithm used for overlapping and dissolved polygons, so some small discrepancies are expected.  Note that we are overhauling and improving the split polygon algorithm for the forthcoming Pro 3.6 release, so the results will be more similar to the overlapping case for high precision polygons.

Split polygons don't make sense for Service Areas with only a single facility and may be slower to generate, so if you have only one facility, you should choose Overlap.