Where travellers pay to go and fish (8)
I believe the answer is:
turnpike
'where travellers pay' is the definition.
(a toll gate where travellers must pay a toll)
'go and fish' is the wordplay.
'go' becomes 'turn' (synonyms).
'and' means one lot of letters go next to another.
'fish' becomes 'pike' (pike is a kind of fish).
'turn'+'pike'='TURNPIKE'
'to' acts as a link.
(Other definitions for turnpike that I've seen before include "Old barrier" , "Toll gate/road" , "Old gates across a road to prevent passage until a toll was paid" , "way in the US" , "Toll road (hist.)" .)