-Why would the 13/40 flyover to cloverleaf help traffic? Normally flyovers are better.
In this location it's a low-volume movement, and didn't need to join 295 South and continue as a lane. Normally, flyovers are preferred, but it wasn't needed here. As mentioned, operationally, it works better now.
1) OK ok so let me get this straight...right now I-295 SB from the DE Bridge toll plaza is 4 lanes to the 95 NB exit
Not really. I-295 South is 4 lanes from the toll plaza to the 13/40 split, then it's 3 lanes wide. The "4th lane" starts as an onramp from 13 South to 295 South, but is really just an auxiliary lane for exits to 495 North then 95 North.
3 lanes to the 141 exit
2 lanes from the 141 exit to the 95 merge just before the 141 overpass
Yes & Yes.
The project now will do what exactly?
-Will it add a lane on I-295 SB so it retains 3 lanes from the 141 exit to the 95 merge (will that be the shoulder)?
It won't add a lane immediately, but sets everything up to add a lane in the future. To be honest, I'm not sure why they won't add the lane now. They're already doing the work, and there's nothing to indicate they'll widen 95 south of here in the future, so there doesn't seem to be any purpose in not doing it right now.
-Where will the merge occur, just how far after 141 underpass?
Immediately after 141.