The council agreed to ask Main Roads WA to lower the limit from the default limit of 110km/h to 80km/h on the Eglinton access road in May 2013.
At the March 23 Two Rocks Yanchep Residents Association meeting, Yanchep Police Sergeant Jason Macander said 80km/h signs had been installed that day.
Sgt Macander said installation of the signs meant police would start enforcing the lower speed limit.
He said traffic was likely to increase along the road between Marmion Avenue and Wanneroo Road as the Allara Estate developed.
The sergeant said he still had concerns about road safety at a 90-degree bend in the road.
�I really do hope that in that development of that area, they cut that corner,� he said.
�If someone is speeding down there without local knowledge, they might go straight ahead into a house or dune.�