In the past trains were stam poweres. They went fast, at the time trains were going at 80kms per hour, people thought that the speed would stop people from breathings or that the vibrations would vibrate them unconcious. Rail travel was cheap and trains made transpoting goods and people more eficiant.
Trains in New Zealand are now mostly used for delivering goods, though some still take passengers. Kiwirail is the main fraight train company that freights goods all around New Zealand. There are currently 4,128 km of track that is used for passenge and freigh trains in New Zealand.
I think that in the future trains will be driven by robots. They might float and could reach very high speeds of over 3000 km per hour. I think they will be silent and that they will be very accurate, never derail, and run to time. I think they will be very safe, if they crach into something they will float upwards and no-one will be hurt.