Grass, direct shortcut for drivers (3,3)
I believe the answer is:
rat run
'shortcut for drivers' is the definition.
I know nothing about this answer so I can't tell whether this works.
'grass direct' is the wordplay.
'grass' becomes 'rat' (both can mean a snitch or informer).
'direct' becomes 'run' (running is a kind of directing).
'rat'+'run'='RAT RUN'
Can you help me to learn more?
(Other definitions for rat run that I've seen before include "'Side-road used to dodge traffic (3,3)'" , "Busy rush hour side road" , "'Busy side-road during rush hour (3,3)'" , "Side street much used by cars in rush hours" , "Busy rush-hour side road" .)