The calculation is straight forward. The coefficient given for rolling resistance is 0.0004 for rail which means that .0004W is the frictional resistance of the track. Given a train going at velocity v then the train is accelerated by friction at a rate of -.0004W/m (F=ma so a=F/m) which is equal to -.0004g (W=mg).

Then to stop it will take t = v/.0004g which means that you will travel vt/2 in that time.

For example, if a train is cruising along at 30 mph (44 fps) then it takes 44 ft/s / .0004(32.2 ft/s^2) = 3416 seconds to stop which means that the train travels 14.2 miles under ideal conditions.