OK< ucl's are unclassified lanes or ucr's unclassified roads, basically roads normally white or yellow with broken edges showing there is no edge definition or kerb.
You also need to look for lines of green crosses, these are BOAT's, Byways Open to All Traffic, there are also green lines that look like an inverted T, these are RUPP's, Roads Used as Public Paths .. there shouldn't be many of these, but some are still marked. Check your maps key for further details ...
Then comes the hard part, check with the local council if these lanes etc are still open to vehicular traffic. They should have a definitive map, maybe on-line if you're lucky, but most probably not!
When you get to the lanes check before you drive them that they don't have a TRO, Traffic Restriction Order on them, this is usually an A4 paper with a map showing the route of the TRO and reason for it being granted.
Don't be tempted to drive them without this knowledge first ... a section 59 order isn't a joke ...
