I think you need to a bit of "Research" before you come up with such an"Opinion"............the demand for a new zone was not something which was suggested because of "Bifurcation".This has been going on for quite some time.
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On the case of Visakhapatnam - A lot of people(Vizag Division) opine they never ever even wanted to part of ECoR but it was enforced by the Railway Board.So you can understand their "Frustration" especially when you see how trains like Prashanti and Vishakha were snatched from them and extended to Bhubhaneshwar even though...
more... the trains were doing exceedingly well and not giving them their fare share of new trains given that it is the "top grossing division" in ECoR.There are other important issues like providing older rakes and shabby maintenence of station(BZA is better station than VSKP as far as the overall feel goes),to be honest.....all stations are bad as far as hygiene goes considering the way the area between the tracks look but if you remove that aspect and consider the general aspects then BZA is better.Giving you an example by taking two important stations within a state.
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The bifurcation of A.P looks a lot more animated,controversial than the bifurcation of Bihar.I totally agree with you that Jharkhand has been on the receiving end of some harsh treatment over these years and i don't know if the representatives have put forth any suggestions or demands either for a better treatment in the "Railway Budget" or "New Zone" per say whereas during the bifurcation of A.P,the "Group Of Ministers" looking over the process discussed the sops which they were planning to give to the Seemandhra region in case the state is divided as far as Railways go.
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P.S - Personally speaking,i don't think there would be any new zone....it's like "Saying what people wanna listen".It's all just "Good ol talk" and nothing more but if does happen then it would be a good decision and i would be equally happy if a new zone comes up for the state of Jharkhand or even for Kerala as those all are justified demands no matter how complex the process is because "Railways" are meant to serve the masses irrespective of the state or region they belong to and if a region has suffered due to some "Petty Politics" in the "Railways" then it's time,that mistake "IS CORRECTED".