With the variable-depth truss, the top chord follows the dead load moment diagram, providing greater depth where it is needed. Traditionally, this configuration leads to a savings of material, but this does not always translate into a lower cost structure, as fabrication and erection costs increase due to the wide variety of member sizes, lengths, and orientations.

The depth of the truss would vary between 50 feet at the end portals (at the ends of the bridge), to 100 feet above the intermediate piers. The floor system would be similar to the other two alternatives. Lateral bracing would be in the form of K-bracing.

The variable depth continuous truss represents a tried-and-true solution to a major river crossing, and would be similar in appearance to the Grace Memorial and Silas Pearman bridges further downstream.

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