Midland MLA Michelle Roberts said she was angry at continued delays in fixing the dangerous intersection, with Main Roads still assessing council plans.
The upgrade has been partially funded by Commonwealth Black Spot Funding, with $250,000 provided two years ago to begin works.
Despite funding and final plans being approved more than a year ago, Mrs Roberts said she was upset to learn that the Main Roads had not approved the upgrades as they had issues with heavy vehicle access requirements.
�I was advised in writing that this was a done deal and that Mundaring Shire and City of Swan�s plans for the upgrade were to take place and be completed by early this year,� she said.
�I have been lobbying the councils and State Government for years to upgrade this dangerous intersection.
�As a result, Mundaring and Swan gained Black Spot Funding and plans were drawn up, which Main Roads agreed to in principle.
�Main Roads WA just comes up with delay after delay.�
A Main Roads spokewoman said there had been discussions on reconfiguring heavy vehicle access from the Farrall and Morrison roads intersection to the junction of Great Eastern Highway and Farrall Road, and developing an immediate or short term treatment to utilise the existing Black Spot funding allocation.
She said Main Roads was waiting on more information from the Shire about heavy vehicle access.
Main Roads traffic ffficers would meet representatives of the heavy vehicle industry, City of Swan and the Shire of Mundaring to resolve the issues in coming weeks.
Mrs Roberts said she had written to the Transport Minister twice in recent weeks seeking a clarification on the matter.
�This is an incredibly busy intersection, with yet another crash occurring there two weeks ago,� she said.
�In 2012 a 25-year-old man was killed at this intersection as a result of a two-car collision.�
Mrs Roberts said the matter was urgent.
The Shire of Mundaring said there were complex issues with heavy vehicles and traffic planning, which Main Roads were aware of, and were working with both Mundaring and the City of Swan to resolve.