Consultation on what are bound to be major and contentious changes to the state highways that run through central Dunedin is expected to start in the next few months.

And the NZ Transport Agency has promised the public will be given the chance to have its say.

It was announced early this year the city's busy state highway, which carries 31,000 vehicles a day, could be cut to one two-way road running through the city, to incorporate the new $1.4billion Dunedin Hospital.

The hospital will be built between the Cumberland and Castle Sts one-ways systems.

The change, the preferred option in a report released by the Ministry of Health, included reducing traffic in Cumberland St, making Castle St the main north-south arterial route and slowing traffic in St Andrew St.

The ministry report noted the one-way streets on either side of the hospital sites were significant constraints to the sites, and a barrier to access.

The agency said at the time some traffic might be rerouted through Strathallan, Thomas Burns and Frederick Sts.

Traffic problems have been a hot topic in Dunedin in the past few years, particularly the cycleway build on the highway.

But agency regional relationships director Jim Harland said yesterday consultation would allow the public its voice, as well as stakeholders.

Meetings were held late last year on the issue of the one-ways that included the University of Otago, Otago Regional Council, Port Otago and the Chamber of Commerce.

Mr Harland said consultants were about to be appointed for the project.

They would do a detailed analysis of the issues the area faced, do traffic modelling and develop a list of options for the network.

The consultants needed to come up with best long-term plan for vehicles, cyclists and pedestrians, improve safety for all and improve the city's livability.

There was a problem with the system in that it was not always clear what the best routes through the city were for the likes of trucks or cyclists.

Consultation could start late this year, but it was more likely to begin early next year.

The feedback would be considered, and recommendations would go to the agency, Dunedin City Council and Otago Regional Council mid-next year.

A business case would be developed for government funding for the work.

Mr Harland said he expected, because the work was being developed to fit in with the new Dunedin Hospital build, it would be favourably considered.