One item for consideration in the future is allowing users to flag unsafe portions of a route and then having that visible to other users (and also influence the algorithm).
Allowing users to flag unsafe portions sounds like a good work-around.
FWIW, I'm looking at the routes it's planning from my home and they aren't safe. It's sending me down heavily trafficked country roads with little to no shoulder. I'll email you some screenshots.
For anyone else experiencing something similar, try the 'Avoid potentially unsafe roads' option in the settings menu. This tells the routing algorithm to always avoid 'secondary' and 'tertiary' roads without explicit sidewalks (these are OpenStreetMap road classifications).
This isn't on by default because in some countries/regions, such roads are very reasonable to run on.
Clearly there's a better middle ground though, which might involve highlighting potentially problematic parts of the route in the UI.
Thanks again js2 for your email and all your feedback!
One item for consideration in the future is allowing users to flag unsafe portions of a route and then having that visible to other users (and also influence the algorithm).