Firstly, congratulations on the route planner, Richard: you've come a long way since RoutePlanner on the Amstrad CPC! I've only just found your planner: I've been using CycleStreets for a while. Your planner has some very nice features, not least the larger view of the map and the route dragging.
Sorry if the following questions are answered somewhere: I tried hunting round the site.
How are the "cities" chosen? I was interested that round Durham there are quite a few places, like Brandon, Spennymoor and Houghton-le-Spring, which are small towns or villages rather than cities. Whereas the large town of Beeston near Nottingham is not represented.
I like the automatic days out suggestions. I had a look through the Durham suggestions, and the last one was Finchale Priory. I'd like to understand why it only gets one star, and why that particular route is shown. Why does the route not use OSM Way 31637938 and Way 41971583? They are both tagged bicycle=yes and highway=bridleway or track. What extra tags would help persuade your engine to use them? The have been given a tarmac surface recently, as part of an upgrade to encourage cycling. I couldn't find anything on your site to explain which tags you take account of. Cyclestreets has a page which explains how they interpret the tags. Looking at their guide I guess if I added bicycle=designated for those ways Cyclestreets would be happier about using them. Would that also be sufficient for your planner?
The route to Finchale is described as 5% traffic free, which is technically true for the route which has been picked. But Frankland Lane is extremely quiet because it only goes to the farm. It hard to work out automatically which roads are likely to be quiet!
It's highly amusing that it starts you off on a narrow back-alley close to the city centre: maybe that's where the Durham place name point is? Does it take account of cafes and things like that when judging the destinations to pick and how to rate the rides?
The only other comment I had was that it would be good if the map tiles had more names of buildings at higher scales. We were trying to give some advice to someone who was visiting Durham, and wanted to get from the station to the Premier Inn. See http://cycle.travel/map/journey/13210 for the route I suggested. I knew vaguely where the Premier Inn was, but when I zoomed in the name did not appear so I had to consult openstreetmap.org to be sure I had got the right building.
Anyway: thanks for all the work on this excellent route planner. I will certainly be making more use of it.
Do you have any plans to allow linking from city pages to the local cycle campaign groups? The data for some groups' area of interest will be available from cyclescape.org.
All the best,