Comment by samcrawford

I wrote a long reply to someone on the Graphhopper forum who was trying to do similar to you. This may be helpful: https://discuss.graphhopper.com/t/can-someone-make-a-video-t...

I'll probably write a blog post on how it's built though - there's quite a lot going on under the hood!

Supporting cycling is a possibility for the future. I don't think you'd want to absolutely exclude non-cycleways (as it might make many routes impossible), but you could certainly weight very heavily against them and show on the map which parts of the route were dedicated to cyclists vs which were not.