[electricron]

To simplify, Norfolk Southern wants to maintain those tracks at Class 3 specifications (60 mph passenger - 40 mph freight). Shucks, that's what they want to maintain all their rail lines at. It costs significantly more money over time to maintain tracks at Class 4 or Class 5. They're wanting either the State or the Feds to pitch in that extra money.
I've written this before, and I'm writing it again, the freight railroads will not allow faster than 90 mph using shared tracks on their corridors. The only way you'll see faster than 90 mph is if some government agency owns and therefore controls the corridor. The sole exception being UP's Chicago to St. Louis corridor, where UP agreed to the higher speeds in a past merger closing. Even so, UP expects someone else to pay to implement and maintain the higher speeds on that line.