I checked in on the "new" Tappan Zee Bridge website, and I found something interesting. The "boards" from the two scoping sessions held in October are now online as a PDF. Board 16 has cross-sections that answer my question as to how the lanes would be divided under these plans. Here's the north span:
There would be four twelve-foot lanes, a ten-foot shoulder, an eight-foot shoulder, a twelve-foot "shared path" for cyclists, pedestrians and skaters, and a twelve-foot "emergency access" lane.
The south structure would have all that, minus the shared path. But what's this? It says, "To facilitate construction, the north structure will be built first, followed by the south structure." And here's what the north structure would look like "during construction" of the south structure:
Funny, it looks just like our existing 82-foot bridge, with an extra lane added!
This seems like a straightforward way to replace a bridge, and maybe that's all it is, but something smells. Does it smell to you? I'm not really sure what Cuomo and the cranky old highway engineers at the State DOT are up to, but allow me to indulge in some wild speculation:
1. Are they actually planning to build the second span any time soon? It could be the ultimate cheapskate tactic: build one span that will add a lane and eliminate the expensive barrier transfer, and never deliver on the second span that will yield the promised shoulders, shared path and "emergency access." By that time, Cuomo will be President and the new Governor can announce that, sorry, there's no money for the south structure!
2. If they build both structures, how long does anyone think the extra lane will be reserved for "emergency access"? My guess is that as soon as the new bridge is open, at the first traffic jam some enterprising politician will start the clamor to have the "emergency access" lane opened to general traffic. That assumes that people will still be able to afford to commute by car across the bridge in the same numbers they've been doing it. That in turn assumes that a wave of outrage will have already persuaded Cuomo to call off the planned doubling of tolls and pay for the south span with income tax money (twist his arm!), and that gas prices won't have risen too high.
3. How much longer after that do you think the shoulders will still be there?