Hours in transit leading to former trading hub (8)
I believe the answer is:
carthage
'former trading hub' is the definition.
(ancient city)
'hours in transit' is the wordplay.
'hours' becomes 'h'.
'in' indicates putting letters inside.
'transit' becomes 'cartage' (process of carrying in a cart).
'h' put inside 'cartage' is 'CARTHAGE'.
'leading to' acts as a link.
(Other definitions for carthage that I've seen before include "It fought the Punic wars against ancient Rome" , "Ancient Tunisian city" , "Chart age of Dido's ancient city" , "Phoenician city state near modern Tunis" , "Ancient N. African city" .)