My own made route. Been driving ONE train around looking for problems......moving trees, smoothing ground, etc. So, I smoother some ground and move some trees.....I did this several times. No problem. But, the last time when I went back to driving, another train (just like the one that I had been driving) was on the track right ahead of me and either at a dead stop or moving towards me. We crashed. WHY? I had only ONE train on the track.