Anybody who has ever cheated on auto expenses knows you can easily squeeze out an extra 100 bucks on parking and tolls.
My business truck has a set deduction amount they allow per miles driven. (less than 50 cents per mile deduction) We don't pay for tolls, yet, in this area and I never pay to park while at work.
I guess you don't have a source?
I think most people take the standard per mile deduction.