Aside from slower speed limits at some points, commuters from Canberra's north to the city won't have major disruptions for another 12 to 18 months, because the first stage construction is about 500 metres off Majura Road.

ACT politicians stood shoulder-to-shoulder with Infrastructure and Transport Minster Anthony Albanese on Tuesday morning for the first sod turning.

But it is apparent bulldozers have already been hard at work, clearing a width as wide as two football fields to make way for the dual carriageway.

When completed in about June 2016, the 11.5 kilometre carriageway will become a major heavy vehicle thoroughfare.

Work will include 11 bridges, three separate interchanges and on-road cycle lanes.

Mr Albanese said the parkway would relieve pressure from Canberra's roads and make it easier to move from north to south of the city.

"What it does is not only cement Canberra as the national capital, but the capital of the region," he said.

"This will make a huge difference in terms of freight, in terms of productivity, which is why it was identified by Infrastructure Australia as a priority project."

Mr Albanese said the project would create 350 jobs while providing big benefits for the ACT and southern NSW.

"The benefit is not just for those who travel on it, it is those who travel in residential streets and other areas of Canberra who will have cars taken off their roads, but most importantly heavy vehicles taken off their roads," he said.

ACT Chief Minister Katy Gallagher said the project would be very inconvenient in the short term for Majura Valley residents. In the long term, traffic would more than double on the parkway.

About 18,000 vehicles a day use Majura Road. By 2030 this is expected to increase to 40,000, including 6000 trucks.

Mr Albanese rejected the notion building new roads only created demand for more roads.

He said people's journey in the future would not be held up at intersections and traffic lights.

Trucks would travel straight through from the Monaro Highway to the Federal Highway, and in the opposite direction, without stopping.

Director of Roads ACT Tony Gill said work would be done in two sections.

The first section from the Federal Highway to Fairbain Avenue would be 500 metres off the existing road, causing minimal impact, except trucks entering and leaving the site.

"Once we get past Fairbairn Avenue it is more complicated, working within the existing network," he said.

The ACT Government and Canberra Airport would be working through different scenarios for managing traffic to maintain access to and from the airport from the city.

"We want to progress the project while not unduly disrupting the public. We are conscious of commuter times, but also travel times to and from the airport," he said.

He said that although motorists would likely try alternative routes, these routes were already quite busy.

"We are not sign-posting particular alternative routes," he said.