After a recent accident at the Catalina Drive intersection involving school students, Mandurah MLA David Templeman called on Mr Nalder and Police Minister Lisa Harvey to take action before a fatality occurred.
Mr Nalder said installation of traffic signals at Catalina Drive would not address the wider issue of the level of access for the Lakelands area.
He said the level of service at the Catalina Drive intersection would improve when developers Peet and Co built extra accesses to Lakelands at Lake Valley Drive and Banksiadale Gate.
The extra access points were part of the area�s development approval and are yet to be built.
The alternative access points would alleviate the need for traffic signals at Catalina Drive in the longer term
Mr Nalder said Peet and Co had previously advised Main Roads that the company would deliver both intersections earlier to provide better access to the shopping centre and overall subdivision.
He understood final designs were being arranged with the aim of construction this year.
Mr Nalder has asked Main Roads to review the cause of the recent crash to determine if any interim traffic management measures might be required.