Transport for Wales faces a list of repairs from the damage caused by Storms Ciarra and Dennis.
There were more than 350 reports of physical or verbal abuse against staff on trains in Wales last year, according to Transport for Wales.
Extreme rain and flooding meant the track foundations were washed away in a number of places between Newport and Abergavenny.
'Significant damage' was caused to the Wales and Border route during the weekend's heavy rain.
TfW says it puts customers "at the heart of decisions", but passengers say overcrowding, delays and poor conditions are a common occurrence.
The Welsh government's warning that the metro could be delayed because the UK government is prioritising preparations for a no deal Brexit.
Transport for Wales (TfW) has warned passengers disruption and timetable changes will continue all week.