RailFans don't miss their train. Why? Because they go to the station HOURS before the actual departure of their Train - to watch OTHER trains depart. - Prince Maan

By having dedicated elevated semi HSR tracks (MPS : 160kmph) along specific stretches like Arakkonam to Jolarpettai and Chengalpattu to Virudhachalam there can be decent savings in runtime of ~1hr in routes connecting important cities with Chennai. Assuming cost/km of such tracks is 100cr this would cost ~30K cr.
But such stretches should be taken up first which can later be expanded to cover entire mainlines !!

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