Inconclusively see off on a travel route (6)
I believe the answer is:
seaway
'a travel route' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Maybe you can see a link between them that I don't see?
'inconclusively see off on' is the wordplay.
'inconclusively' becomes 'se' (I can't explain this - if you can you should give a lot more credence to this answer).
'see off' becomes 'away' (synonyms).
'on' means one lot of letters go next to another.
'se'+'away'='SEAWAY'
Can you help me to learn more?
(Other definitions for seaway that I've seen before include "Channel open to ships" , "Inland route for use by seagoing ships" , "Route for a vessel" , "Ship route" , "Channel for shipping" .)