Stop when confronted by a snake on the road (7)
I believe the answer is:
asphalt
'road' is the definition.
(I've seen this before)
'stop when confronted by' is the wordplay.
'stop' becomes 'halt' (halt can mean to stop).
'when' becomes 'as' (eg 'when I walked' means 'as I walked').
'confronted' becomes 'p' (I am not sure about this - if you are sure you should believe this answer much more).
'by' is a charade indicator (letters next to each other).
'as'+'p'='asp'
'halt' put after 'asp' is 'ASPHALT'.
'a snake on the' is the link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for asphalt that I've seen before include "Substance used in roofing and paving" , "surface of path" , "Bitumen" , "Mixture of tar and gravel used in road surfaces" , "Road surface material" .)