Transport by car and railway (5)
I believe the answer is:
carry
'transport' is the definition.
(I know that transport can be written as carry)
'car and railway' is the wordplay.
'and' is a charade indicator (letters next to each other).
'railway' becomes 'ry' (abbreviation for railway).
'car'+'ry'='CARRY'
'by' acts as a link.
(Other definitions for carry that I've seen before include "Bring" , "Be pregnant (with)" , "Transport, fetch" , "Transport; transmit" , "(Of sound) be audible at a distance" .)