Richard Fairhurst wrote:Essentially (I'm over-simplifying a bit), fast draggable routes and customisable routing parameters can't coexist. You can precompute the best routes between key destinations, which is what cycle.travel does (and Google, and most of the big commercial sites), but that "bakes in" the route preferences to the database. Or you can compute everything on the fly when the user asks for a route, which means you can offer adjustable weightings - but that means thousands of route permutations, so it's impractical to precompute stuff, so the routing is slower. (There's huge amounts of research on the topic if you're interested...)
I think there's room for both approaches. brouter.de is very good if you want something customisable.
That's interesting. Since cycle.travel seems to tend to suggest solely road routes, would it be possible to have a layer showing sections of off road tracks and bridleways etc.? The ability to drag waypoints is good, but I think users need to have some idea of the existence and whereabouts of off road sections in order to alter a road route to include them. If there were a layer of off road sections, users would be able to see more readily if those sections might be a good modification to the route initially suggested by cycle.travel, and then be able to drag waypoints to them.
If such a layer is possible and off road sections are graded in OSM, would it be possible to represent that in the layer, e.g. green colour coded tracks for easy tarmac tracks through to red for tracks which are muddy or technical?