I've looked at the greenway site and don't see anything listed.
There's a near-identical bridge over I-95, at the ~298 mile marker and straight east of Palatka, like the one over I-75. I'm assuming there's some kind of greenway there.
This is at the ~342 mile marker over I-75 and is signed as the greenway.
This is the bridge over I-95 with no signage.