How is the walking distance in Network Analysis calculated?

[HelenaBreuer]

I am generating service areas with Network Analysis for transit stops (on ArcGIS Pro).

I am using Generate Service Areas tool, and using walking as the travel mode and setting it to 0.25 miles- I want to see what region of area lies within 0.25 of traverse-able walking distance.

I would like to know, how is this walking distance calculated? Does the walking distance account for non-traverse-able areas?

My concern is that the walking distances include buildings, rough terrain, or private areas that a pedestrian cannot walk through to get to the stop - thus the actual walking distance is longer (they have to walk around the building or said private area). 

If it is not calculated, would I need to import a shp file of Buildings for the study region, then import that into the "Polygon Barriers" layer of the service areas layer? If so, then would the walking distance calculated account for the buildings and restrict the paths from them?

[MelindaMorang · Accepted solution]

The walking distance is calculated along roads and walking paths only.  It will not have pedestrians walking across buildings, forests, lakes, open areas, etc., unless the network itself has a specific pedestrian-traversable path going through it.

[HelenaBreuer]

Okay great - that is what I was hoping for. 

So I do not need to add any roads or anything to the service layer? All I have in the service layer is the transit stops under Facilties, nothing else. After I imported those, I edited the travel mode and cut offs, and output geometry. Does the network analysis handle the roads and such on the back end?

I was told network analysis is complex and takes a lot of time, although this seems rather easy and simple... just want to make sure I am doing everything correctly.

[MelindaMorang]

From your initial post, I believe you're using the Generate Service Areas Ready-to-Use tool.  This tool uses the ArcGIS Online services to calculate the service areas, so it's using the Esri-provided network dataset and tools behind the scenes, concealing most of the complexity from the user (you).  So, I think you're doing everything you need to do.  You can read the documentation (linked above) to learn more about the various analysis options to make sure you've configured the tool for your needs.

The one word of caution I have is to be aware of credit consumption.  Service Areas can eat up a lot of credits if you have a ton of transit stops, so just be aware of the credit charges by checking the table here.