Turn this into a general notifications stream for all users.  

New forum posts being followed, new PM's and new location data etc. could all be sent to this stream.  Later when and if you can follow a user, this information could also be sent to the notifications stream.

All activities on the site you are monitoring including railcam updates could be sent to the notifications stream.  Once this is running it is very easy to move this streeam to an RSS based feed or even for a notifications centre APP for iOS or Android or both.

Thinking more about it, what about having the notifications stream advised you of new jobs and also new train location information as I have just mentioned in the forums?

A notification stream is a central listing of all activities on the site the user is monitoring.