I was on my way to school an I was running late.On the way to school is a via duct(you could either go over or under it).I always go under . Half way under there are 4 sets of train tracks. As I get to the tracks there is a slow moving traingoing east . Once I see the end of that train,I pick up my bike I'm riding an start to walk by as the end of the train passed by. THEN as I start to cross the next set of tracks I hear a horn blasting , It's a west bound Amtrak 20-30 yards away coming very fast. I was already in the middle of the tracks. I just didnt break my stride forward an made it across. As soon as I was off the tracks, all I felt was the wind an vibration of the train on my back.A split second judgement to turn around would have certainly killed me.