Is it possible to bridge the highway along the river that way without the current putting undue pressure on the piers? Having it go across is one thing, but going along the river out in the water itself would present problems, correct?
I suppose you would want pilings similar to freeway overpasses, to let the current pass through, rather than solid, wide piers like you would see on a bridge crossing a river.
I’ll leave the engineering to someone who knows what they are doing. But I don’t see where the stress on the piers couldn’t be solved with enough cash. I do understand that due to the shape of the river, it might require piers in stronger current than normal, as the strongest current would normally be bridged over.