The way that I would try to answer your original question is to add a field to your roads and update it with a count of vertices.


Add a Long Integer field
Calculate that field using the Python parser to be equal to !shape.pointcount!,


You can then use the vertex count field as, or to contribute to, your impedance field.

You'll need to think about whether an almost straight road with lots of vertices should be treated as "straight" for your purposes, and maybe also about how you will deal with roads that consist of many lines.

@user30184 has offered some very useful advice as a comment that I will append here:


  Probably it would be best to clean the roads from unnecessary dense
  vertices by simplifying. Alternatively you can think about other
  measures like a ratio of mathematical distance from the start node to
  end node vs. the length along the road or something like that.


Prefer Straight Routes for wayfinding?
I was browsing through this and was wondering what progress in quantum gravity research has taken place since the (preprint) publication.

If anyone can provide some helpful feedback I would be greatly appreciative.
