Road safety features in cases yet to be resolved (4-4)
I believe the answer is:
cats-eyes
'road safety features' is the definition.
'cases yet to be resolved' is the wordplay.
'to be resolved' indicates anagramming the letters.
'cases'+'yet'='casesyet'
'casesyet' with letters rearranged gives 'CAT'S-EYES'.
'in' is the link.
(Other definitions for cats-eyes that I've seen before include "Line of reflective studs as road markings- very feline" , "Middle-of-the-road reflectors" , "On the road, they reflect light" , "Reflecting devices embedded in roads" , "Light-reflecting studs set into road" .)