Theme park transport (4)
I believe the answer is:
tram
'theme park transport' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for tram that I've seen before include "Street vehicle running on rails" , "Vehicle running on rails in road" , "Take it to the mart" , "Road vehicle running on tracks" , "An early form of Luas in Dublin transport" .)