There are quite a few ways to interact with MS SQL Server from R, but things seem more limited when it comes to spatial data. I figured out a way to have my cake and eat it too.
Reflecting on things I wish I'd known when I started graduate school.
I used Google Cloud Platform to do some heavy lifting with R. Here's a quick guide to get started.
Making networks out of rasters turned out to be trivial with R.
Converting a polyline layer to a network object isn't conceptually complicated, but implementation can be finicky. Here's one way to do it with ArcGIS.