Network Dataset solver choosing a longer route

Question

I have built a Network Dataset for Lower Hutt City (NZ) and am trialling out the routing. The solver has decided to jump on the motorway and head up north instead of south to a on-ramp that heads up the hill.

When I explore the network I can see intersection is connected?, so unsure why the solver chooses to head up north instead of south.

Any ideas?

Melinda Morang · Answer

For anyone looking at this issue in the future: The ArcGIS Pro documentation now includes a guide for troubleshooting unexpected network analysis results and problems with user-created network datasets: https://pro.arcgis.com/en/pro-app/latest/help/analysis/networks/troubleshoot-network-analysis-problems.htm.

Melinda Morang · Answer

The likely culprits for this type of problem include:

* The network is disconnected somewhere. It may not be at the intersection you expect, but it could be at some on-ramp or other intersection along the expected route.
* Some roads along your expected route are incorrectly restricted to travel.
* Your cost attributes are calculating the travel cost incorrectly.  Either that highway has an unexpectedly low cost, or some other road along your expected route has an unexpectedly high cost.
* You have some sort of turn restriction preventing travel from one road to another.

See this post for some tips on how to debug and diagnose the problem.