The Quebec government will tear down the Turcot highway interchange in Montreal and replace it with a modern ground-level system, CBC News has learned.

Government sources told CBC's French-language service, Radio Canada, that Julie Boulet, Quebec's transport minister, will formally announce the $1-billion project on Friday.

The sprawling tangle of overpasses and elevated ramps that connect highways 20, 720 and 15 is more than four decades old and has reached its life expectancy, transport officials said.

The province will bulldoze the interchange once an alternative road system is built, said Montreal borough councillor Ronald Bossy, who consulted on the project.

"They are going to be building a second autoroute on the ground before they dismantle [the interchange], and then when that's done, they're going to take the other one out," he said in an interview with CBC News.

The project will take at least a decade and will likely cause huge disruptions for Montreal drivers. About 300,000 cars use the interchange every day, according to Transport Quebec.

The province inspected several highway structures earlier this year after the Concorde overpass in Laval collapsed last September, killing five people.