Indian Railways now runs around 10000 Passenger Trains every day. Plans to increase the number of trains has resulted in an unexpected change in Indian Railways.
Currently the Passenger Train Numbers are 4-digit numbers and this does not allow Railways to introduce new trains. So from 20th December 2010, the Train Numbers have been converted to 5-digit numbers.
The transition has been made smooth by a simple logic – All existing scheduled & regular running express, mail, superfast trains will have the new train number by prefixing ONE (1) to their existing number.
Special trains will have the new number by prefixing ZERO (0) to their existing number.
Furthur, passenger trains & sub-urban trains will also be renumbered to adhere to the new 5-digit system.
Press release on Southern Railway can be read here.