Traffic using the area may experience severe delays for the next seven months.
The project, just west of the existing T-junction, will include traffic lights, dual carriageways on Reid Highway through the intersection, a double turning lane on Reid Highway into Lord Street and a realigned section of Lord Street to provide separate right and left-turn lanes into Reid Highway.
Reid Highway carries more than 25,000 vehicles per day through the Lord Street intersection and more than 10 per cent of those are heavy trucks.
In the five years to 2012, there were 169 crashes at the intersection and drivers nominated it as seventh worst in Perth in the 2012 RAC Red Spots WA survey.
A Main Roads spokeswoman said the City of Swan will construct the new junction and speed restrictions will be in place.
‘Standard work hours will be 7am to 4pm Monday to Saturday, however some night works will be required at times and may include lane restrictions,’ she said.
‘Once the work is finished, the existing section of Lord Street from Reid Highway to Coast Road is likely to be decommissioned.’
The current intersection will remain open until the new one is completed.
Swan Hills MLA Frank Alban said the long-awaited safety initiative was a great asset to the region.
‘This project now has the provision for future expansion to the south, meaning these intersection upgrades won’t just benefit us immediately upon completion, but will continue to be beneficial and relevant for the region well into the future.’
Swan Valley Regional Network co-ordinator Sue Hurt said residents were supportive of the upgrade.
‘The timeframe needs to be really tightened and there needs to be a detour management plan to ensure traffic is managed as the intersection is being built,’ she said.
Work on the project is expected to be completed by the end of April.