Zulu Eleven wrote:I really don’t understand why people are so wedded to OSM as a mapping source.
The rights of way data on there is very often utter sphericals.
For £20 quid a year you get access to the whole country on OSmaps - an organisation that spends hundreds of millions of pounds every year developing the best mapping in the world, that you can actually navigate with, and if you know how to use one can even work out where you are with when your GPS gets jammed by the Russians
You even also get a downloadable OS Map with every paper map you buy.
Ok, I'll bite.
I'm a big fan of Ordnance Survey and always have been - from here I can reach out to a shelf full of modern OS maps, a complete collection of the New Popular Edition, and CD-ROMs of 1:50k from about 15 years ago. Their 1:50k cartography is probably the best mass-market mapping in the world (with due deference to Herr Imhof). OS maps are great.
If what you want is to look at a complete map of public rights of way in England & Wales, then OS is unbeatable. OS (by law) gets updates directly from PRoW officers, while OSM relies on volunteer edits. OS, as you say, has a budget of hundreds of millions to spend on the UK alone; OSM's annual budget is about £200k for the whole world. If a display map of PRoWs is what you want, then OS will always win hands down.
But there are many, many other considerations for cycle mapping.
OS PRoW data isn't routable (other than in National Parks, weirdly). The footpath and bridleway lines drawn on a Landranger or Explorer map that you see are just that; lines drawn on a map. OS doesn't have a database saying "this bridleway connects to this byway here". That's why there are no bike routing websites that route using OS data.
OS has a very partial selection of points of interest. For example, there are two public water points on the Ridgeway between Streatley and Ogbourne. Neither of these are marked on OS maps. (They're not mentioned or marked in the KAW guidebook, either, which slightly surprised me.) OS has some pubs but no cafes, let alone bike shops.
OS maps only come at the scales they choose. 1:25k is ideal for walking and 1:50k is ok for some types of cycling. For longer distance cycling then a scale of 1:80k—1:125k-ish is often best (Richard Oliver, the unofficial historian of the OS, has written extensively on this) - but OS cartography at 1:100k is an ugly mess, and their data products don't permit you to make your own countryside mapping at that scale, even if you could afford them.
OS is not great at showing waymarked cycle routes. (It has the NCN, sometimes, a bit out of date.) OS doesn't even attempt to map urban cycling infrastructure. OS doesn't record path surfaces, or obstacles like stiles and gates. And so on.
OSM fixes all of these. Not consistently, because it's made by volunteers. But the fact that almost all cycle mapping tech is now OSM-based - Garmin, Wahoo, Strava, countless mapping sites including RWGPS, CycleStreets, Komoot and (ahem) cycle.travel - illustrates that it's good enough for most purposes. It's clearly even good enough for Cycling UK, given that the King Alfred's Way page uses OSM (though given that CUK is using OSM's volunteer server resources for free, it would be kind to have the mandatory credit in a font size you can actually read). There is much more to OSM data than is surfaced on openstreetmap.org itself, and a smart app or site can really bring out the richness of it.
And I'm a bit bemused by your point about the Russians - if you have offline mapping on your phone (or Garmin or whatever), you can still view it without a GPS signal whether the data is from OS or OSM.