A campaign for a Garden Island Highway to relieve traffic congestion around HMAS Stirling has hit a speed bump.

The State Government has knocked back a request from the City of Rockingham to examine the feasibility of building a highway.

The city has long advocated for improved local and regional transport access to HMAS Stirling, Australia’s largest naval base, on Garden Island.

There have been queues nearly 2km long in morning peak hour from the HMAS Stirling entry to the corner of Parkin and Bell streets.

A council report earlier this year said without works such as the Garden Island Highway and a four-way roundabout at the intersection of Hymus Street, Parkin Street, Point Peron Road and Safety Bay Road., the road network was likely to collapse by 2030.

The city resolved in March to ask the State and Federal governments, as well as various State and Federal politicians, the whereabouts of a highway feasibility study announced in December 2024.

In a letter to the city dated August 21, Mr Cook said the State Government recognised the need for detailed transport planning to ensure access to HMAS Stirling. But this did not extend to holding a feasibility study for the development of a Garden Island Highway.

Mr Cook said the State Government’s priority was to support the delivery of “practical, targeted upgrades” that would improve access to HMAS Stirling and address current congestion.

A technical assessment by Main Roads in 2025 said a new Garden Island Highway was not the preferred solution because it was forecast there would not be enough traffic to justify it, could have an impact on the environment and residential amenity, and would be complex to build.

Mr Cook said upgrades to existing local roads were the most “effective, practical and timely” approach to fix the traffic issues.

He said Main Roads had started the first phase of the Garden Island transport network improvement plan, which included traffic data collection and concept design development.

“This stage of Phase 1 is expected to take six to nine months to complete,” he wrote in his letter.

“The investigations will define the scope, alignment and cost of upgrades to the existing road network, including Point Peron Road and Memorial Drive, comprising the section behind the Returned and Services League Hall.”

Deputy mayor Robert Schmidt said he spoke to government ministers about the Garden Island Highway while in Canberra for the Australian Council of Local Government and the Australian Local Government Association National Congress in June.

The city also wants State and Federal funding for upgrades to Point Peron Road, Lease Road and Memorial Drive, a Cape Peron transport needs study, and a transport strategy for the wider Rockingham peninsula.