The trains were not running

again yesterday. 
You would think it would be a fairly simple thing to keep our small rail network running - and running on time as well. Apparently not.
I had pedalled over to the railway station to catch the train to a meeting and was greeted with a morose, "Trains aren't running again."
The commuter who muttered this to me was heading back to his car. 
An elderly couple came out of the underpass. I could hear them wondering how to call a taxi so they could get to a medical appointment. I offered the use of my phone - accepted.
My own situation was a little more difficult. I didn't want to leave my trike at the railway station and get a taxi. It was damaged once and stolen on another occasion (I got it back). I also didn't have enough money for a taxi. I don't carry that sort of money with me unless I absolutely have to. 
So, I headed home. I phoned the leader of the meeting. He was sitting at another railway station. It is an odd one, only accessible on foot. He thought the train was just delayed. I explained. He swore fluently and said,
      "I'll call my wife and get her to get me again and pick you up as well."
The initial problem was on another line. There have been numerous problems on that line since it was "electrified". Our line still runs on diesel trains. It makes no difference though. If one line is "out" then the whole system goes out for some reason. It seems that the computer system cannot cope. 
There were gates down at level crossings. That added to the chaos.  There were roadworks somewhere else. More chaos. 
Nobody appeared anywhere. There was a brief announcement about an "unexpected delay". It advised people to "make other arrangements". Fortunately yesterday was still inside the school holiday period or the chaos would have been even worse.
I know there will sometimes be problems, problems that nobody can foresee and that cannot be helped. I do wonder though that a modern computer system can't be programmed to take into account a failure on one line and keep the others running.
Is that really so difficult? Can someone please explain?