Full charge for travelling open road (12)
I believe the answer is:
thoroughfare
'road' is the definition.
(thoroughfare is a kind of road)
'full charge' is the wordplay.
'full' becomes 'thorough' (similar in meaning).
'charge' becomes 'fare' (fare is a kind of charge).
'thorough'+'fare'='THOROUGHFARE'
'for travelling open' is the link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for thoroughfare that I've seen before include "Main road" , "Public way or street" , "highway" , "Road or path" , "Public road" .)