Direct links to Liverpool South Parkway and therefore access to LJA.
Direct service potential from Wales, Shrewsbury etc.
Possibly easier links to Manchester from stations south east of Hooton if Merseyrail put 3rd rail to Helsby.
Freight link into Liverpool and Runcorn.
Option for commuters to avoid Runcorn Bridge tolls.
This is one of twelve schemes covered in the Liverpool City Combined Authority (LCCA) transport plan that was going to be revealed in more detail in September so the timing, apart from the political motive, is curious except perhaps for the fact that according to NR the cost for the scheme is reduced if it is completed as part of the Wavertree to Weaver Junction resignalling project which is due to be completed in 2016. Presumably, the details of plan need to be fully worked and the costs incorporated to the budget etc. and this explains the surprising early announcement. Interestingly, the plan at point 7.4 f states
"Connecting via Halton Curve
Improves connectivity of the Liverpool City Region with Cheshire North and South Wales."
The full report can be read at the following link
http://councillors.knowsley.gov.uk/...trategy.pdf?StyleType=standard&StyleSize=none
This would suggest restoring a direct service from Lime Street to Cardiff via Chester, perhaps through extending an existing service which would also facilitate point in 7.4a
"Improving National Passenger and Freight Connections
Improves Liverpools poor level of connectivity with other major cities across the UK. Identifies schemes which will enhance the provision of routes for freight to cater for the expected increase in rail freight into and out of the Liverpool City Region."
The freight aspect is a bit of a puzzle as I can't think of a flow from the Wirral Peninsular to Liverpool which would use the link as containers would travel by the feeder vessel from Liverpool to Ellesmere Port, although I did hear a story of biomass moving from Ellesmere Port to Fiddlers Ferry but don't know if it is a long term contract. The main freight use I can think of would be the movement of steel to and from South Wales or the West Midlands to the Gladstone Steel Terminal in the Port of Liverpool, as well as aluminium and perhaps paper to various points in Wales and West Midlands all of which currently moves by road, or WCML. This would then free up capacity on the WCML for intermodal/container traffic also to and from the Port of Liverpool as the scheme completes after the opening of the Liverpool2 riverside container terminal at the end of 2015.
As Merseytravel is responsible for developing transport policy in the region on behalf of the LCCA I would have thought that developing a passenger service over the route would be on the cards, although initially a diesel service from Wrexham or Chester or even Llandudno. If Chester to Crewe or Manchester is electrified, I would suspect the line would be electrified with OHLE rather than 3rd rail, which might mean Merseyrail could have a requirement for dual voltage stock, home perhaps for some 313's?