The train lines have gone bizerk: there was a signal problem earlier and now the trains are all backed up. They're stopping at each station for 5-10 minutes.
I had taken the longer route but mid way I decided to change direction and stopped to get on the reverse direction. The trip probably took as long as it would have had I continued. But for some reason the stoppages had become frustrating. The wait for the train to re-start seemed much longer than it actually was.