Transport taking 50 people up? (5,3)
I believe the answer is:
cable car
'transport taking 50 people up?' is the definition.
I can't judge whether this defines the answer.
'transport taking 50 people up?' is the wordplay.
'transport' becomes 'cab' (cab is a kind of transport).
'taking 50' becomes 'l' ('L' can be a synonym of '50'. I am not sure about the 'taking' bit.**).
'people' becomes 'race'.
'up?' shows that the letters should be reversed in order (in down clue: letters go upwards).
'race' written backwards gives 'ecar'.
'cab'+'l'+'ecar'='CABLE-CAR'
(Other definitions for cable car that I've seen before include "Conveyance for passengers to mountain top" , "An easy way to 6?" , "Transport used to go up mountain" , "could make one upwardly mobile" , "Funicular vehicle" .)