Because the railroad portion is a separate issue. The tollway will be privately funded, with the front money recouped in truck and car tolls. However there is a legitimate question if such a user-fee system would work for freight railroads, for a variety of reasons. While there is need for some capacity enhancements for rail, most of the $10 billion of proposed projects are more for safety issues (removing road/rail crossings and getting most freight traffic out of urban areas, where the impact of hazmat accidents could be far more catastrophic.) Also some of the projects would allow for reuse of the rail lines/ROW for transit, trails, or new roads.
This is just one idea for funding, and I'm not endorsing it (though keeping an open mind, I'm leaning towards voting against.) I'm certain that the $10 billion list of projects contains several proposals that are of marginal benefit and simply pork.
Raise the taxes on those rail yards and the businesses will find cheaper land. They probably have some low, favorable rates.
In the State Constitution?? Public works projects do not belong in the Constitution of any state. We just voted to recind our Bullet Train here in Florida. Rest assured, we still believe pregnant pigs should have constitutional protection.