Network Analyst will not route across International Dateline, even while using WGS 1984. Any advice/

Question

I am working on a project that involves routing across oceans and I keep running into an issue when I try to route or create a service area that crosses the International Dateline (IDL). When my network dataset was created, it created additional junctions at the IDL. Yet, any time I try to route across these, the route terminates. I have made sure that the map wraps around in the map properties. But it still won't solve the way I need it too.

Any advice?

Cheers,

Gideon

Gideon_Singer_Abt · Answer

Thanks Melinda, let me work backwards from you questions!

* I am using ArcGIS Pro 3.1.3 and can confirm the Network Dataset has been rebuilt after each round of edits. 
* There is no time of day or TimeZone table involved. Strictly using distance for calculations. 
* The Feature Class, Feature Dataset, and Environment Settings are all using a geographic coordinate system (WGS 1984).
* The issue appears to occur around where the International Dateline zigzags around in the WGS 1984 projection.

The one thing I haven't tested, other than eyeballing it, is the network connectivity at those junctions. I'll see what's going on with the Explore Network Tool to see if there is indeed a connectivity issue between the lines on either side of the junction that was auto created when the network was built. Just to note, the lines that run across these boundaries are single line segments that are getting a junction added to them around the IDL.

Melinda Morang · Answer

Hmm, I don't think we have enough information yet to figure out exactly what's going on, so let me ask a few follow-up questions and suggest some possible causes.

Does your network dataset have a TimeZone table and attribute?  If not, then I don't think the problem you're experiencing has anything to do with the date line because the network wouldn't even be aware of it.

What projection or spatial reference are you using?  I believe some projected coordinate systems break in the middle of the Pacific Ocean and actually don't wrap all the way around the world.  So maybe you  need to choose a different coordinate system.

Have you verified that the network is actually connected in these locations?  You can use the Explore Network tool to click on the line and see whether it's properly connected to its neighboring network edges.  If it's not connected, you might need to read about network dataset connectivity: https://pro.arcgis.com/en/pro-app/latest/help/analysis/networks/understanding-connectivity.htm

Are you solving your Service Area or Route using a time of day, or is it time neutral?  If you solve it without setting a time of day, do you experience the same problem?

Maybe a dumb question, but did you remember to build your network dataset after making any edits to it?

(Please also tell us what version of Pro you're using.)