The Charroterie will have temporary lights from the end of August till March 2027 to enable 70 new flats to be built.
The Charroterie is a key route to the west of the island from St Peter Port.
But, from Monday 24 August, temporary traffic lights will be put up to allow work to begin on Court Falaise.
Builders estimate it will take 19 months to put up the 70 affordable flats, which sit in front of the Montville Drive cliff face.
Over the past year the rock face has been stabilised with mesh and reinforcing rods.
Bus times for routes like the 95 to the airport will be altered as there will be delays, especially at peak times.
Lisa de Kooker, the chief operating officer at Guernsey Housing Association, says they are aware it will cause some inconvenience:
"We are very grateful for the public’s patience whilst this work is carried out.
"Court Falaise will provide much-needed affordable homes for the island, and these are necessary arrangements to progress the
development.
"We will continue to work closely with the States of Guernsey to ensure traffic arrangements are maintained and disruption is kept to a minimum
where possible.”
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