There is none also depending on where you live and where the package is going it will narrow down the possibilities but you will not know which hub your box will fly into until your label is printed
When you label is printed here are the code that tell you which hub will be used
A Fort Worth TX
W Oakland CA
N Indianapolis IN
X Memphis TN
Q Los Angeles CA
Numbers In state
I live in GA and based on shipping over the last 7 years I will say that 90 percent of my packages go through memphis and indianapolis, a few have went into Fort Worth, therefore Memphis and Indianapolis are really the ones I pay extremely close attention to.