Turnpike (7)
'turnpike' is the definition.
(I know that turnpike can be written as tollway)
This is all the clue.
(Another definition for tollway that I've seen is " where one pays for US passage".)
(Other definitions for route that I've seen before include "Course to be travelled" , "Way, path" , "Itinerary; way" , "Course, road" , "track" .)