Point-to-point speed cameras along the Forrest Highway between Lake Clifton and Binningup are ready to go live from September 6.
The cameras three month trial has ended and will now be made permanent on both sides of the Forrest Highway with fines to follow.
Extensive testing found almost one-third of 500,000 drivers monitored over that period were speeding.
About 10 per cent of them were doing so by more than 10km/h.
Road Safety Minister Michelle Roberts told The West an advertising blitz would be held before the cameras were turned on to warn drivers to think about their speed.
“This education campaign, which will include TV, radio, digital ads and billboards, begins two weeks prior to enforcement and gives drivers plenty of notice if they speed on the Forrest Highway they will be caught."
The cameras are on both sides of a 27km stretch of the Forrest Highway between Lake Clifton and Binningup and determine if a car was speeding by calculating its average speed.
The cameras can detect if a car is speeding when it enters or leaves the zone and infringements can be issued regardless of the average speed.
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