The design will allow north-bound traffic to avoid the roundabout and continue on the East Tamar, while south-bound traffic will need to negotiate the roundabout.

The final design also avoided the use of traffic lights, which were originally planned for the intersection.

Works are expected to be carried out between September and April, with speeds reduced to 40 kilometres per hour and traffic restricted to one lane during the construction phase.

Infrastructure Minister Michael Ferguson said the government had responded to community concern about traffic lights and adjusted the plans accordingly.

Slide across to see before/after plans for the Mowbray Link-East Tamar Highway intersection (allow several moments for load time):

"Our traffic engineers have been working through what is the best way to address the risk, to use the government grant that's been provided, to get the best possible safety and transport efficiency outcomes," he said.

"Part of the process that we always undertake is to share our plans with the community, listen to feedback, and at times we're prepared to change our designs in light of that feedback.

"This is the best design to get the best outcomes for the travelling public and it's testimony to both our traffic engineers and designers, together with the contractor's designers, to work up a model that works, especially having listened to the community around traffic lights."

The traffic lights plan was criticised by the RACT, Windermere MLC Ivan Dean and a City of Launceston councillor, and received negative feedback from the community, forcing the government back to the drawing board.

It was considered an unsafe option and would add to a cluster of traffic lights further south on the East Tamar Highway and Goderich Street.

An overpass was the community's preferred choice, but Shaw Contracting general manager safety Jim Irvine said there were time and cost constraints, and the roundabout was the safest option of the three.

He said south-bound travel times were unlikely to be increased too much, and disruptions during the construction phase would be minimal.

"The additional impact will be very, very minimal to the road users," Mr Irvine said.

The Mowbray Link upgrades were part of a suite of infrastructure works on the East Tamar Highway, Goderich Street and on other Inveresk roads in the coming years.

Plans for traffic lights at the intersection of Goderich and Gleadow streets were criticised by community members at a consultation session last week, with some fearing it would only worsen congestion in the area.

The government will next turn its attention to the Lindsay Street intersection in anticipation of further growth in traffic volumes through the area.