Showing concern about railway transportation (8)
I believe the answer is:
carrying
'transportation' is the definition.
(I know that carrying is a type of transportation)
'showing concern about railway' is the wordplay.
'showing concern' becomes 'caring' (I've seen this before).
'about' means one lot of letters goes inside another.
'railway' becomes 'ry' (abbreviation).
'caring' going around 'ry' is 'CARRYING'.
(Other definitions for carrying that I've seen before include "Maintaining" , "Transmitting; transporting" , "Conveying, transporting" , "Transporting - pregnant" , "providing freight service" .)