Part of their motivation is to mitigate the bicycle bottleneck created by their arbitrary closure of a stretch of Greenbelt through the neighborhood the mayor developed. They call it their "nature trail," and it's closed to bicycle traffic. After all... it's common knowledge that the fragile ecosystem and the furry and feathery woodland creatures can thrive while surrounded by pedestrians, dogs, lawn mowers and backyard barbecue parties, but would be irreparably harmed by punks on bikes.
Okay, I've vented. (And I've vented before.)
A couple weeks ago I rode out there to get the lay of the land. A half mile or so west of the "edge of civilization" (the last houses) on the south side of the river, I came across a sign announcing the closure of the Greenbelt. (I've got to hand it to the Garden City Fathers... they are good at closing the Greenbelt!)
Shortly past the sign, there are stakes in the ground, which I imagine mark the trajectory of the pathway and bridge that should start taking shape any time.
In this photo, taken from the south side of the river, you can see a stake in the foreground, and on the other side there's a small clearing, pretty much straight above the stake... I imagine that's where the bridge will meet the north bank.
Here's a rendering of the bridge, taken from the Garden City website:
(If I were in charge, we'd spend a few extra bucks and make it look like a tiny replica of the Golden Gate Bridge.)