Electrical device suitable in construction of road (7)
I believe the answer is:
adaptor
'electrical device' is the definition.
(I've seen this before)
'suitable in construction of road' is the wordplay.
'suitable' becomes 'apt' (I've seen this before).
'in' means one lot of letters goes inside another.
'construction of' is an anagram indicator (I've seen 'construction' mean this (answer constructed from certain letters)).
'road' with letters rearranged gives 'ador'.
'apt' placed inside 'ador' is 'ADAPTOR'.
(Other definitions for adaptor that I've seen before include "Connector for differing plug types" , "Tap road (anag)" , "Connector (O, not E)" , "Device for connecting multiple plugs (O, not E)" , "Electrical device" .)