"You've got quite a bit of information. Why not share it with the Open Street Map project?"

OSM is a worthy project aimed at providing truly public mapping, copyright-free, from volunteer collected data.
At first thought, TrailWise data would seem to a valuable addition for OSM.

Unfortunately, most of the data in TrailWise would be regarded as 'tainted' by the OSM project. It's not that there's anything wrong with it, it's the source of the data that is the problem.
Most TW data will have been derived from Ordnance Survey mapping in one form or another; perhaps directly by reading off a Landranger paper map in the field, or reading off the official Definitive Map at the council offices (which is drawn over a large-scale OS map).
The Ordnance Survey view that kind of data as 'derived data', being derived from their maps. They claim legal ownership of such derived data.

GLASS, as the legal body behind TrailWise, holds OS licences to use OS derived data in certain ways, but of course the licence doesn't extend to granting any further rights to other people or to the general public over what we hold. We have no way of telling which, if any, of our data was collected truly independantly of OS mapping - but realistically we know it would be only a tiny proportion.
Sadly, there is no legal way to supply to our data to OSM's satisfaction as copyright-free.

If you think that is an odd attitude for the OS to take, you might be interested in the Free Our Data campaign.

You may contribute your own data (e.g. GPS-read points or tracks) to the OSM project.
But - please do NOT blindly copy TrailWise data to the OSM - you really wouldn't be helping them at all.