At the weekend, I got on my bike, and cycled from London to Oxford. Take a look at a map, and there's a road that starts in London, and goes to Oxford. It's the A40.

Since the M40 was built, much of the A40, certainly from Denham Roundabout to Wheatley has most of it's former traffic on the motorway. This makes it an excellent route for keen long-distance road cyclists.

However, from the Marylebone Flyover to White City, that stretch used to be the A40(M), an urban motorway. Nowadays, it's just the A40, not a motorway any more. Being an intrepid cyclist, I set out to see if it could be cycled along. Technically, and legally, the answer is yes. There are no signs along there saying you can't cycle (or walk, or ride a horse) along the elevated sections.

However, the Marylebone flyover doesn't have a hard-shoulder, nor does the White city flyover. Technically, even cyclists shouldn't be cycling on the hard shoulder, but I doubt that police would stop a cyclist for that.

The speed limit along much of the Westway is currently 40mph, which doesn't make it any worse than cycling along the North Circular Road.

The only other cycle-hostile parts of the route were from Uxbridge roundabout to Denham Roundabout. Though technically legal to cycle the A40 there, there's a sign saying 'Unsuitable for cyclists'. Quite true. Fast moving traffic, a 70mph speed limit, and no hard shoulder.

This leads me to ponder if cycle route planners might want to have a tag for roads that, while technically legal, are termed hostile, and not recommended for novice cyclists eg. bicycle=hostile, or whether this could be implied by the speed limit and other factors?

I've just removed bicycle=no from the Westway, because it was untrue from a technical and legal standpoint. Suggestions welcome from anyone involved in cycle routing using OSM data.