I believe that is not practical. The costs of enhancing a barrage to accommodate an all-weather highway compromises the design of both and ends up more expensive than building each separately. It might, just might, be feasible for a very broad and shallow crossing such as Chesapeake Bay or Ijsselmeer but not for the Mersey.What are the chances of a new cross-river road or even light rail system on the top of this barrage?
If this became a barrage with a tolled road on the top of it, it could compete with ....
Yes, huge locks would be needed.... or at the north at New Brighton.
... If the barrage was at the north of the river it would of course interfere considerably with shipping.
You don't half like artificial geographies. You affiliate to a fantasy "Wirral" identity (when it's a collection of discrete suburbs like Hoylake, Heswall, Tranmere, Wallasey) and now you seem to be merging NB with Egremont and God Knows Where Else.......bits of Liscard and Wallasey Village..........!!!?!!!?!!!!?!!!!! into an artificial "North Wallasey" construct. "North Wallasey" indeed! Where did you get that from? Is it a new zone imposed by "Wirral" Council to denigrate the constituent towns of their artificial and unpopular composite "borough"?In New Brighton there is a very vocal and determined NIMBY brigade who have, rightly or wrongly, managed to scupper many a potential project. Neptune have taken over a decade to get permission and acceptance for a massively compromised (from their point of view) scheme.
The people in North Wallasey were prepared to knock back 75 million pounds worth of investment.
This scheme would never be accepted in North Wallasey due to the huge changes it would make to what is a beautiful environment, the noise and the fact that it would ruin the view.
I don't believe that residents of Wirrals "rust belt", should have to suffer noise and compromised views either, but if there is to be a barrage, due to the already industrial nature of that part of the Wirral you would expect that it will be placed there....and I suspect Peel know this and that's why they aren't pushing for it to be further up river.