Just as Killaloe is to have a new bridge, so too is Limerick. Or perhaps more than one …. This page (on a site whose ownership I do not know) has a map of proposed routes for the proposed Limerick Northern Distributor Road, which is to provide a northern bypass of Limerick. You can read about it on the websites of the promoters, Limerick County Council, Clare County Council and Limerick City Council. You can download stuff. And you will be pleased to hear that there are to be consultations (only not many of them).
This road is to be built in two phases, the first covering the area from west of the city to Parteen and the second from there to the old Dublin road (N7 as was, now demoted to the status of boreen). There are (or were) several options for each section, but the decision to cross the navigation at the Ardnacrusha tailrace, between the power station and the existing bridge, seems to be set in, er, concrete: that is, it seems, where the ESB wants it.

Ardnacrusha and the tailrace seen from the existing bridge at Parteen
The current consultation is about Phase 2, south-east from Parteen. There are several possible routes.
Two of them, B1 and B2, would cross the Shannon downstream of Plassey and the Black Bridge; they would not cross the Plassey–Errina Canal. It would be important to ensure that they did not further damage the towing-path and its artefacts on the Limerick side.

The west bank below Plassey
Four other routes — C1, D1, D2 and E1 — would cross the Plassey–Errina Canal between Gillogue and Wooden Bridge; they would cross the non-navigable Shannon upstream of Plassey, between there and a point just above the confluence of the Mulcair. C1 seems to run very close to Gillogue Lock, although that may be an effect of the scale of the route markings.

Woodenbridge (which isn't)
I am sure that the ESB will look after the interests of the existing navigation (through Ardnacrusha) and that Waterways Ireland will look after those of the former navigation (the river to Plassey and the canal thence to Errina). However, it might be worthwhile lobbing in a comment to TPTB, first to sttress the heritage value of the abandoned navigation and second to suggest that a new road near Plassey might improve rather than diminish access to that area.
One final thought: this new road seems likely to put the final nail in the coffin of the Limerick Tunnel under the Shannon estuary downstream of Limerick. I very much enjoy using the tunnel, but many folk are deterred by the charges and they drive through the city instead — or, worse, cross the Shannon at O’Briensbridge. As a result, revenue is less than expected, so the traffic guarantee mechanism means that the National Roads Authority has to compensate the tunnel operators.
So now that a new, free, presumably fast road is to link the east and west sides of the city, what will happen to the numbers of vehicles using the tunnel and to the taxpayers who are ultimately paying the compensation? They’ll pay more. The tunnel is on a national primary route, so it’s the NRA’s problem, whereas the new bypass is a regional or local route, which is in the hands of the local authorities.
=p-po-