Oban and Utah combining to build fast transport link (8)
I believe the answer is:
autobahn
'fast transport link' is the definition.
(motorway in Germany and other countries)
'oban and utah combining' is the wordplay.
'and' says to put letters next to each other.
'combining' indicates anagramming the letters.
'oban'+'utah'='obanutah'
'obanutah' anagrammed gives 'AUTOBAHN'.
'to build' is the link.
(Other definitions for autobahn that I've seen before include "Great way" , "way abroad" , "high-speed route" , "expressway" , "overseas route" .)