For any future editors: I had spoken with a city engineer about this during one of the pre-construction public meetings about the project. He told me the redundant southbound bike lane is intended for cyclists immediately going from Holton to Water (no need to get to the other side of the road just to cross back), and is to compensate for there not being a stoplight at Reservoir/Glover. If you can't safely get on the cycletrack before the bridge, there is a stoplight at Brady where the redundant painted lane ends, and there is a painted area showing you where to wait during the two-part turn onto the cycletrack itself.