Twitter thread on map generation: given some constraints and parameters, grow an imaginary island, country or city based on a few random seeds. https://twitter.com/ptychomancer/status/980968298002006016
Most are not road-related; the closest I've seen is a medieval city map generator that does lay out Boston-style streets.
Hmm. I'd love to look into this.
One reason I stopped with Open Street Map was the historical and economic restrictions. I just want to build fantasy road maps, damnit.