I found this powerpoint presentation that has examples of the ways to improve the 80 year old lift span, and some of them make sense, the others do not.
Current conditions, 2 10 foot lanes, with a 4 foot 6 sidewalk that is not open
Proposal 1, remove the sidewalk giving two 12 foot lanes.
Proposal 2 was to remove the sidewalk and install a concrete barrier, giving two 10'7 travel lanes, with a jersey barrier in the middle.
Proposal 3 is not very doable due to the span being a movable bridge, it would require redoing of the counterweights as well as new approaches for the outer lanes. also it would have 10 foot inner lanes with a barrier, and 10'6 outer lanes.
Proposal 4 was someone thinking outside of the box imho, double decker bridge with 11'5 lower and 12 foot upper lanes.
Proposal 5 was a very simple proposal, not really needing a picture but it was to reuse the piers and pretty much make a new bridge that was four lanes wide instead of two. Problem is that it would close the bridge to all traffic and cost the bridge comission money in uncollected tolls
i think option 1 is the best one for the span, giving the widest lanes for the lowest cost, requiring the least modification to the span.