[Tagging] "byway" vs "track" ( was: highway=track access )

[SomeoneElse]

Dave F. wrote:
>
> Going slightly off topic, I notice the UK listing is missing byway, a 
> recognised highway classification.
>
> Dave F.

Is there a notable physical difference between a "byway" in England and 
Wales and a "track"?  "Byway Open to All Traffic" and "Restricted Byway" 
are both legal definitions (i.e. "designation" tag), but is there a 
physical difference too?

The one class that I'd possibly suggest as being missing are quad-bike 
trails used by farmers in upland areas, but I really don't have a good 
suggestion as to what to tag those as.

Cheers,

Andy