Means of escape from trains - railway inspections:

The means of  escape from  trains is also considered  in  NFPA130.     Some  of  the considerations are:

At least two emergency exits should be provided from each carriage.

It should be remembered that the carriage may not be upright when people want to use the emergency exits and the design should not hinder escape if the carriage is not upright.

The means of escape from train carriages should be safe even when the train is crowded to its full capacity.

Sometimes fire modelling is used to determine the worst case expected behaviour of fire and smoke in a carriage.   Computational fluid dynamics would be the expected modelling technique.  Also, evacuation modelling has been used to determine how people evacuate from carriages and how long they take to do so.

When carriages are fixed permanently into position NFPA101 considers them simply to be buildings and that Code applies in such cases.