Where will projected I-80 revenue go?

In light of the FHWA questions to the Turnpike Commission - specifically about whether I-80 revenue will be used for debt services for non-I-80 expenses, and how payments to PennDOT can be considered "operating costs" - I have put added up the numbers (see spreadsheet below or link here).

Toll Roads News has a related analysis, and has posted the Turnpike Commission's presentation that contains the numbers.

As this shows, less than 40% of the I-80 toll revenue would go back into I-80 for maintenance, capital construction, and debt repayment related to I-80. In contrast, the thirty-six year plan calls for almost half the revenue to go to payments to PennDoT. (There is also $8 billion in "surplus" which primarily accrues after 2040). It is curious how they will justify this as simply an "operating cost" of I-80.