I am using Esri libraries in a Xamarin Android (C#) project. I'm pulling a list of MapPoints from a PolyLine and examining the M value. As the number is increasing while I traverse the list, I assume it is a cumulative total distance measure of some sort from the origin point. No matter what kind of tweaking and torking I do though, I can't make this value look like the total distance, or even get to the same order of magnitude. I've tried degrees -> km, and various other attempts at conversion. (I'm in WGS84 spatial reference).

I don't do much routing, but my understanding is the M corresponds to a weight of that route. So a two lane hwy would have a higher weight than an interstate, and that is used to compute the best route. Shortest not always being the best