It is chiefly a question of BrE usage vs AmE usage, but the meaning is the same as explained here:
Where Americans use transportation, Britons generally prefer transport. In American English, transport is only a verb (with rare exceptions). So where Americans say public transportation, transportation commissioner, and air transportation, Britons say public transport, transport commissioner, and air transport.
Neither transport nor transportation is right or wrong; they’re just different ways of saying the same thing.
Canadians us both transport and transportation, though the latter has the edge. Australians favor transport.
It is not clear how these regional usage differences developped. What we know is that the usage of transport and transportation meaning “means of conveyance” date back to different centuries; late 17th c. for the former and mid-19th c. for the latter.