Stage one of the project, which forms the new eastbound dual-carriageway of Gnangara Road, is nearly complete after starting in November last year.
From Monday, August 24, traffic will use this section of Gnangara Road as single lanes while the stage two upgrade takes place on the existing road. Simultaneously, Beechboro Road North will be closed at the intersection of Gnangara Road and Beechboro Road North for two weeks while the intersection is rebuilt.
The second stage of the project involves upgrading the two-lane road that forms Gnangara Road in its current form and will serve as the westbound carriageway upon completion.
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READ NOWCity of Swan Mayor Charlie Zannino said disruption to motorists would be minimised.
"We know our community is very supportive of the Gnangara Road upgrade project and this is a significant milestone," he said.
"People will need to plan ahead during this period and use alternate routes."
Detours will be in place via Alexander Drive and Lord Street, and also via Great Northern Highway and Reid Highway for heavy vehicles heading south on Great Northern Hwy.
Access for local traffic in and out of Beechboro Road North will be maintained via the roundabout at Beechboro Road and Hepburn Avenue.
Gnangara Road's upgrade came after an extended community campaign.
The intersection of Gnangara Road and Beechboro Road was named among WA's most dangerous intersections while the road itself was named the most dangerous.
The project is on track for completion early next year as construction crews work day and night.
More information about the project and the construction stages is available online at website www.swan.wa.gov.au/GnangaraRoad.