TRANSPORT group Sewta, the South East Wales Transport Alliance, says  plans to widen the M4 around Newport could actually make traffic worse in the area.

In its response to the Welsh Government on consultation on options to alleviate the motorway bottle-neck around the city, Sewta says upgrading the M4 between Magor and Castleton without dealing with other roads in the area could just make matters worse.

It is, instead, calling for a comprehensive strategic transport network to reduce reliance on the M4 and boost the economy.

There are concerns about the impact of traffic flow on strategic junctions further east and west - such as on the two-lane stretches of the M4 at junction 23 at Magor, Coryton, and junctions ont he A48 at Cardiff.

Sewta also says it has "fundamental concerns" that data being used in the consultation document is over five years old and unreliable.

It says potential changes in the Severn crossings tolls could have "profound implications" for levels of congestion on the M4.

It is also calling for measures to prevent more development near motorway junctions, something which has generated a lot of local journeys.

Sewta is favouring option A, which it says would mean an extra crossing of the River Usk and provide extra road capacity - this is also the option favoured by Newport council and would see a new £830m road built to the south of the city.

However, it says all the options being looked at have significant limitations because of "weaknesses in the evidence available to support them."

And it says the scale of the funding of three of the options will "present major challenges".

Sewta chairman Cllr Andrew Morgan said: "Funding sources beyond those which would conventionally be considered for invesment of this nature will need to be identified."

The response says the long timescale of any work - upgrading the motorway may not be completed, it says, until 2031 - means that public transport investment in the interim is a necessity.

Sewta's own proposals inlcude a fully electrified rail network, a Metro for the Newport travel to work area, bus priority corridors from Cardiff, Blackwood, Newbridge and Pontypool into Newport, a new bus interchange in Newport, new rail services from Ebbw Vale and Abertillery into Newport, better train frequency between Abergavenny, Chepstow, Bristol and Newport, new rail stations at St Mellons, Coedkernew, Ebbw Vale Town, Crumlin, Pye Corner, Caerleon and Llanwern, new park and ride schemes at Abergavenny, Pontypool, Chepstow and Severn Tunnel Junction, faster journey times, full timetable and ticketing integration and better informaton for passengers.