It depends on the time, place and convenience, Whichever is convenient at that point of time is my preferred mode of travel.
If I have the time, I would rather travel by train.
In Europe and Japan, train travel is preferable to plane, as distances are covered by train much faster, and for longer journeys, the overnight journey is a pleasure.
In India, any travel over 8 hours during the day by train, I prefer the Plane. For business journeys, plane always unless it is a stupidly small distance like Bombay Poona, Bangalore Chennai or Trivandrum Kochi.
Like I said, convenience holds the key.
But if I had all the time in the world, and in no hurry, I love the Railway.
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For lengthy journeys,I would definitely prefer a train,for we can stretch and lie down in our berth.I dread my to & fro trips between India and USA.It is one helluva experience sitting in one position,even if you walk around at intermittent intervals.Even though,I prefer Lufthansa and have a break journey at Frankfurt the the journey is indeed
tiresome.Travel by train is always preferable.