Thanks for the trail report.
The current bridge has problems:

A large area, perhaps 100 acres, drains through this area. In Spring and after heavy rains, the water level rises to within a couple inches of the bridge decking and expands to cover much of the ground in this picture. For month at a time the bridge stringers are immersed in the water. This whole area is pretty low and soft. The entrance is soft and the earth eagerly sucks up any concrete or stone we've added their to armor it. At the Tuesday ride this week, it looked like this:

We would like to address these issues by building a new bridge, taller and longer, to avoid the boggy areas. I'm not a fan of hard cornering on flat bridges, and so we've straightened the line a bit to make that unnecessary. Our current plan, pending city approval, is to build this new bridge in parallel to the old bridge, and then when finished removing the old bridge and abandoning the existing lines.