I believe roads are one of the most prevalent human made features added to terrains in most CG related environments and it seems to be a common issue in the userbase of World Machine.
There are a couple of papers which describe procedural ways to generate realistically designed roads: example
This would allow you to set A and B as points and connect them with a road that follows a few configurable requirements like a maximum slope and curve angle.
Another very neat thing would be a way to procedurally simulate human settlement, which mostly follow the same principles all around the globe.
example
https://hal.inria.fr/hal-00694525/document