I don't know how big a feature request this is, but I'm going to go for it anyway.
Often I like to do more free-form route planning where I'm trying to identify all the roads and paths I would be happy to cycle on in an area to increase my variety of routes. To do this, I drag points around and see what the routing 'thinks' about different sections.
I understand that the route planner scores roads and paths in order to decide how cycle friendly they are. If it was possible to see this visually, either by a heat map type approach or highlighting roads and paths above a certain cycleability this would be a very useful tool for me.
In any case I am very happy with the service as is!
Comments
Yes! I would love to do something along those lines – in fact I have pages of notes already on the subject.
What I want to do is visualise the ‘hierarchy’. The way that cycle.travel’s route-planner works is that (as you say) it scores each road/path. It then works out the best through-routes formed by linking those good roads/paths together. Eventually it forms a hierarchy of the best long-distance routes, i.e. the best possible score between A and B. Precomputing all of these is what makes it all so fast – so you can drag (say) a Land’s End to John O’Groats route around in real time. (The algorithm behind this is called Contraction Hierarchies.)
Displaying this hierarchy on a map would be terrific, not just in rural areas but also in cities – you’d be able to see (say) the best route across London at a glance. The challenge is getting the hierarchy out from the routing engine cycle.travel uses (OSRM) and I haven’t yet figured out how to do that. But there are a couple of promising avenues so I’m optimistic I’ll work it out before too long.