Inform about road options, by the sound of it, for ordinary people (10)

'ordinary people' is the definition.
(ordinary members of a group)

'inform about road options by the sound of it' is the wordplay.
'inform about' becomes 'grass' (grass can mean to inform on someone).
'road options' becomes 'routes' (routes are options when travelling).
'by the sound of it' indicates a 'sounds like' (homophone) clue.
'routes' is a homophone of 'roots'.
'grass'+'roots'='GRASSROOTS'

'for' is the link.