Can I use 'mode of transport' in the following question? And what is the difference between 'transportation' and 'transport'?
Which type of transportation started its service in 1890?
If this is a question about public transport, then no, you will have to keep the phrasing.
Mode of transport = can be any form of transport, whether private or public.
Type of transportation = railways/trams/trolleybuses/metros/underground trains >> means of carrying members of the public in communal vehicles