Neither man nor machine may turn its back on UID - the railways latest move could just be a testament to this. India's largest employer - the railways - is giving a new, numerical identity to the trains in its service.

All four-digit numbers of trains will make way for five-digit numbers with each number being the unique identity of a corresponding train.

The express trains will retain their old roll numbers, only with a slight modification - the numeral '1' will preceded them. Passenger trains will follow suit with a '0' preceding original numbers for special trains, '5' for conventional passenger trains, '6' for MEMU and '7' for DEMU trains.

Suburban services in Kolkata shall begin with digit “3”, in Mumbai with digit “9” and in other parts with digit “4”. It is now proposed to capture all passenger trains running over Indian Railways for various software applications by giving them a unique number. Thus, there is a need to shift to 5-digit train numbering scheme from a 4-digit train numbering scheme as railways presently operate over 11,000 passenger trains on an average per day while 4-digit scheme can have train numbers only upto 9,999.

The 5-digit numbering scheme will be made effective from December 20.