Caught warning signal: good for driver if it's adverse ahead (6)
I believe the answer is:
camber
'signal good for driver if it's adverse ahead' is the definition.
I can't judge whether this defines the answer.
'caught warning' is the wordplay.
'caught' becomes 'c' (cricket abbreviation).
'warning' becomes 'amber' (amber traffic light).
'c'+'amber'='CAMBER'
Can you help me to learn more?
(Other definitions for camber that I've seen before include "Convex shape of road surface" , "Slight upward curve in road, wing etc" , "Slight convexity, like the surface of a road" , "may appear on road" , "Curvature of aircraft wing" .)