Paul from Quincy, IL on 6/1/2014 8:19:15 PM:
It looks like the question has been answered. But I did notice that there are 120 long term parking spaces at the Amtrak station. There is no agent, so no one is to know you are biking.
I can't answer the "Is is safe?" question, but I routinely leave my van at Illinois and Iowa stations for a month at a time.
"Is is safe?" question usually get answered at
http://discuss.amtraktrains.com/index.php?/forum/3-amtrak-rail-discussion/