IF Britain's biggest port does not get the go-ahead for its next expansion, it will mean even more lorries on the A14 than the extra one million trucks expected.

IF Britain's biggest port does not get the go-ahead for its next expansion, it will mean even more lorries on the A14 than the extra one million trucks expected.

That's the threat today facing motorists on the congested A12 and A14 corridor – and residents on the already under-pressure Felixstowe peninsula.

The new £242 million development plus a recently opened extension is set to generate nearly one million more lorry journeys, but alternative plans for the port would add around 1.4 million to the road network.

Port chiefs told the public inquiry that if the redevelopment of Landguard Terminal to create a massive deepwater quayside was not permitted, they would instead re-open the mothballed former P&O roll-on roll-off terminals.

This would mean another 800,000 lorries using the port each year, plus a further 170,000 likely soon at another ro-ro terminal, 250,000 from the latest extension, and some of the 400,000 currently handled at Landguard.

The port also has another ro-ro berth, currently being used for paper, which could also be used for 400,000 lorries if one day needed.

The Highways Agency is pressing the inquiry for the port to carry out work to the A14 between Seven Hills and the Copdock interchange because it says it will be over-capacity within the next decade if the port expands.

The port has already agreed to pay for safety work to ease problems at Copdock and the Felixstowe dock spur roundabouts, but is contesting the claims about the capacity of the dual carriageway and Orwell Bridge.

No-one at the inquiry has suggested what action might be taken to reduce congestion on the road.

Ian Chadney, senior manager for port development for Hutchison Ports UK, told the inquiry that each of the two former P&O ro-ro berths could be used for just over 400,000 trailers a year.

Chief operating officer at the port, Chris Lewis said currently around 230,000 lorries were using the ro-ro berth at Dooley, most of these Norfolk Line.

This was close to capacity but it may be possible soon, separately from the expansion project, to increase this to 400,000.

"We are at the moment looking at some reconfiguration of the berth and some new vessel types which will enable us to increase that capacity quite considerably at relatively small investment costs," said Mr Lewis.

"It is a little difficult to say at the moment, but that figure will be around 400,000 units."

The expansion scheme will increase the port's capacity to 5.2 million standard-boxes a year, and is expected to create nearly 1,500 new jobs – 621 port jobs and 860 in dock-related employment – within ten years of opening.

It will create a new 1,350m deepwater quay to handle three ultra large container ships and a smaller one simultaneously, plus a new eight-track rail terminal.