The M1 Princes Motorway will be closed for five nights from Sunday for essential maintenance works.
Visitors to Sydney's Vivid festival will be among the motorists forced to make a detour around the busy road.
An 18-kilometre stretch of motorway will be closed in both directions from the Old Princes Highway intersection at Waterfall and Bulli Tops.
The closure will run from 8pm until 4am each night from Sunday, June 4 to Friday, June 9, weather permitting.
Work will include trimming vegetation, clearing drains, litter collection and repairing the road surface, guardrail and signs, a Transport for NSW spokesperson said.
A detour for light and heavy vehicles will be in place via the Old Princes Highway and is expected to add about 10 minutes to journeys.
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