I want to create a service area map of Burma in order to spot the areas that are within xx kilometers from a set of cities.
The problem is that the generated polygons aren't exactly what I expected.
In order to understand why, I tried to generate service areas on a very simple network where the greens dots are my three facilities :
The first network is a simple triangle. We can see that computing service areas on this shape completely failed.
However, if I complexify a little bit the network by adding edges inside the triangle, it runs smoothly :
In front of these results, I wonder if someone can explain to me how a service area is generated. More precisely, how does ArcMap interpolate the values of the polygons in the areas where there are no streets?
Thanks a lot for your help!