Tagging public footpaths for routing

I think it's worth looking at the history of these tags.

highway=footway long pre-dates highway=path and was originally intended for both asphalt paths in towns and footpaths in the countryside. Paths that were cycleable were cycleways (in other words there was a hierarchy, with footway as the lowest common denominator of most of the other highway=* tags, motorway being the obvious exception). There are numerous discussions in the mail archives on these points.

Access tags followed: for obvious reasons. There are many usable paths where the access rights are not shown on most maps and adding this information to OSM was useful. Furthermore different countries have different default access regulations for things like cycle tracks.

A particular problem was defining the legal status of public rights of way in England and Wales. At the outset the original highway tags were adequate, but over time it became clear that something else was needed. After a number of false starts (using access tags) the designation tag arrived and seems to work well.

So what does this mean for path versus footway? There are basically three interpretations of path:

1. A footpath in the countryside (widely used in Germany). In this scheme footway is only used for asphalt paths in towns. In practice this distinction can also be achieved by using the surface tag.
2. A multi-access path: where no single use can be defined which suitably incorporates other uses (this is pretty much the description on the wiki).
3. A path which was not ground surveyed and insufficient information is available about access (by analogy with highway=road).

Generally, then it is best to see what standard has emerged locally for mapping these things.

In the UK usage has oscillated, but the two mappers I would regard as standard setters for footpath mapping (Nickw and SomeoneElse) both prefer highway=footway. The wiki advice regarding footpath mapping (global style) represents the point of view of one individual NOT the consensus of mappers in the UK: in practice, highway=footway has a clear meaning and highway=path does not.

Remember when using footway you disallow bicycles unless allowing them explicitly with bicycle=yes and when using cycleway you disallow pedestrians unless allowing them explicitly with foot=yes whereas when using path you allow both of them. However, these access restrictions also depend on the country, see access restrictions page in the wiki.

There has been no consensus to date on when to use path vs footway vs cycleway. I'd say if it's used (almost) exclusively for pedestrians, use footway. If it's used (almost) exclusively for bicycles, use cycleway. If it's more of a mix, use path.

I'd say the best advice is to be consistent in a given area, and to be sure routers use the data correctly tag foot/bicycle=yes/permissive/designated. This way routers can rely on those access tags rather than on highway=path/cycleway/footway.

Footway × Path I see footway as a paved way for pedestrians intentionally built in the place where it is (pleasant and easy), and path as something that appeared because people are going there (mudbaths and infrequently-used overgown jungles). But this is probably my subjective view, that might be partially based by icons used for this in JOSM. :)
Tracktype should go with track and I am not aware of any "pathtype" equivalent.

Routing I would not rely on openrouteservice for routing - it apparently does not update very often and currently it uses data from 20. 05. 2011 for routing. (I got that problem with my first edit...)

The access restrictions are confusing indeed. I am not if the tag mean physical possibility of going somewhere, legal possibility of going somewhere or its combination. After all the access restrictions correspond much more to common-law system than continental.