A fresh drive to get improvements made to the A47 will be launched today, with experts saying the problem-ridden key road acts as brake on the county's economy.

A new business case claims investment in the road could create 10,000 jobs within 20 years and bring Norfolk a yearly economic boost of �390m.

Dualling the entire 105-mile road would, say consultants commissioned by Norfolk County Council, lead to a 30-minute reduction in journey times along the length of the road from Peterborough to Great Yarmouth.

But, rather than calling for the whole road to be dualled, the plan identifies specific pinch-points which consultants say could be targeted for improvements.

They include:

Dualling the Acle Straight;

Dualling the North Tuddenham to Easton stretch to the west of Norwich;

Dualling the Blofield to Burlingham stretch;

Creating a third river crossing at Great Yarmouth;

Making improvements to the Pullover junction, the Saddlebow junction, plus the Hardwick junction at King's Lynn.

Work at those and other pinch-points would, according to consultants Mott MacDonald, help bring in a further �800m of private investment, while helping the county shed its reputation for being difficult to reach.

The report states: 'In short, as it is currently operating, the A47 is at best a brake on the economic growth for the whole county, including parts of Cambridgeshire. At worst it hinders investment, adds to business and commuter costs, causes disproportionate accident and safety issues, and contributes to the 'peripheral' image of the county.'

Norfolk MPs, county councillors and representatives from the New Anglia Local Enterprise Partnership (LEP), will head to Westminster on Monday to present the case for cash for those improvements to transport minister Stephen Hammond.

Graham Plant, county council cabinet member for planning and transportation, said: 'The coalition has launched a number of initiatives which suggest there is capital funding around, so long as projects are shovel-ready.

'We have been looking at the A47 for so long that we think there are some elements of it which are pretty much ready to go and which we can show would bring economic benefits.

'I'm optimistic the government will listen to us, because we have got the figures which show those economic benefits. We have got the businesses, the LEP and the MPs behind us.'

Businesses have been invited to today's launch at the Norfolk Showground in Costessey, where the business case, and a new A47 Gateway to Growth prospectus will be unveiled.

Speakers at the event will include Mr Plant, Mike Jackson, the county council's director of environment, transport and development, Broadland MP Keith Simpson, the MP representative on the A47 Alliance, and Davina Tanner, from the New Anglia LEP. To mark the event, Mr Simpson will drive the A47 from King's Lynn to Great Yarmouth in his Union Flag Mini.

He will be accompanied by county council staff who will be making a video record and Tweeting from the car using social media website Twitter, as the journey progresses.

The A47 is a trunk road, and as such is the responsibility of the Highways Agency, rather than the county council, so it is up to the government as to whether it is improved or not.

However, the county council believes it could bring in about �110m of local funding to help make improvements.

Today we'll be hosting a day of debate on this issue on our website with live coverage of Mid Norfolk MP Keith Simpson's bid to drive along the A47 from King's Lynn to Great Yarmouth in his Union Jack Mini.