That is the other thing pointed our by railway authorities which is the fact that because there are so many trains running nowadays throughout , there is hardly any gap to avail of blocks so that proper maintenace can be done. If scheduled blocks need to be done for long time, then trains will either have to be cancelled or rescheduled which will add to passenger inconvenience so it is a thin line in balancing both. Scheduled maintenance time for repairs and checks and at the same time ensure passenger & freight operations also run unaffected.