At the end it should have been 2 across the Holly Sub, 2 across the Flint Sub and 1 across the Port Huron Wye.

The one across the Wye involved a curve on the GTW.

The 2 across the Holly involved S-curves.

I would think maintenance was a real issue. Especially considering the GTW unilaterally removed the Holly Sub-Flint Sub diamonds later on.