School initially went ahead with winter transport (4)
I believe the answer is:
sled
'winter transport' is the definition.
(I've seen this before)
'school initially went ahead' is the wordplay.
'initially' indicates taking the first letters.
'went ahead' becomes 'led' (I've seen this before).
The initial letter of 'school' is 's'.
's'+'led'='SLED'
'with' acts as a link.
(Other definitions for sled that I've seen before include "Snow transport" , "Sledge" , "Tray on which to slide" , "Toboggan (mainly US)" , "Sleigh" .)