Transports erupt as motorway starts going against the flow (8)
I believe the answer is:
upstream
'against the flow' is the definition.
(I've seen this before)
'transports erupt as motorway starts' is the wordplay.
'transports' indicates an anagram (I've seen 'transported' mean this).
'starts' suggests taking the first letters.
The initial letter of 'motorway' is 'm'.
'erupt'+'as'='eruptas'
'eruptas' anagrammed gives 'upstrea'.
'upstrea'+'m'='UPSTREAM'
'going' is the link.
I am not very happy about this link. It may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for upstream that I've seen before include "Towards (river's) source" , "at an earlier stage in process" , "Away from the sea" , "contraflow" , "Ma erupts (anag.)" .)