Some roadside notices (3)
I believe the answer is:
ads
'notices' is the definition.
(advertisements)
'some roadside' is the wordplay.
'some' indicates a hidden word (some parts of the word are used).
'ADS' is hidden in the letters of 'roadside'.
(Other definitions for ads that I've seen before include "Promotions" , "Notices" , "Commercials" , "Classifieds (abbr)" .)