(if you can call it that)

• It's a tool, but it plays like a game
• Has a minimal user interface that can create (and edit) road networks with complex features in simple ways.
• With it's internal data structure modelled after OpenStreetMaps to simplify importing datasets (and potentially exporting to it).
• Open source from day 1 13th.

https://www.youtube.com/playlist?list=PLYTjyn6fVp5jeQfhXkXse0o__VBC-VmRB