Deccan Queen - मेरे सपनों की रानी

It is often observed that in Official Railway Maps issued by various zonal railways different classification of sections are mentioned in box chart. This is what railway means:
#ClassificationOfLines :
(1) Broad Gauge – The BG lines have been classified into six Groups ‘A’ to ‘E’ on the basis of
future maximum permissible speeds as under -
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Group ‘A’ - Speeds upto 160kmph
Group ‘B’ - Speeds upto 130 kmph.
Group ‘C’ - Suburban sections of Mumbai, Delhi, Chennai and Kolkata.
Group ‘D’ Spl. - Speeds upto 110kmph and annual traffic density is 20 GMT or more.
Group ‘D’ - Speeds upto 110kmph & annual traffic density is less than 20 GMT.
Group ‘E’ – All other sections and branches lines with speed upto 100 kmph.