Billion-dollar road upgrades to slash commute times

As two of Adelaide's biggest ever road projects near completion, 9News can reveal just how much time motorists in the city's north and south will save when they open.

Together they're costing $1.5 billion dollars to build.

And new pictures show what the $670 million Darlington upgrade will look like when it's completed.

The freeway removes five intersections that currently hold up motorists. And Transport Minister Stephan Knoll says for that investment, motorists will save three and half minutes in travel time for people heading to and from the city.

"For all of those people in the southern suburbs, all the way down to Sellicks Beach as well as everyone who comes up from Victor Harbor and the Fleurieu, they are going to be the biggest beneficiaries of this project," Stephan Knoll said.

And for motorists in Adelaide's northern suburbs, a new $900 million connector will link the Superway at Wingfield to the Northern Expressway.

Commuters will avoid four intersections on Port Wakefield Road, while also being able to travel at 100km/h.

"We're going to save a huge amount of time for people who live in the outer north," Mr Knoll said.

"We're talking up to 8 to 10 minutes that is a phenomenal amount of time." But the Civil Contractors Federation says more still needs to be done and is calling on Governments to fast track new roads and intersection upgrades.

"The Department of Transport with getting out the work and deciding what they're going to do - plays a big part," The Civil Contractors Federation's Melissa Ekberg said.

The Federation says motorists and construction firms are being let down by inaction. It wants Highway One duplicated between Port Wakefield and Port Augusta, which could save motorists up to 45 minutes in travel.

It also wants the final major section of the South Road between Darlington and Hindmarsh given the greenlight as soon as possible.

"That's the decision that the Government needs to answer and we're asking the smartest people in the country, the smartest people in the world what the answer to that question is," Minister Knoll responded.