The Department for Infrastructure and Transport confirmed late Monday, May 31 the large gum trees along the Playford Highway are safe.
A spokesman said there was no requirement to remove any large gum trees in the vicinity of Ropers Road, Cygnet River, as part of the road improvement project currently underway.
Community concern rose after it became unclear whether the trees, located directly on the highway edge, would be cut down.
"The department has undertaken vegetation surveys and in recognition of the importance of the surrounding vegetation and the habitat it provides, the scope of works for the project has been designed to minimise impacts, as much as practically possible, while delivering on the project's safety objectives," a statement read.
"Some native vegetation will need to be removed or pruned, including the removal of four small trees. Any native vegetation impacts need to be approved and offset in accordance with the Native Vegetation Act 1991.
"The Department is also bound by the Environment, Protection and Biodiversity Conservation Act 1999, in regards to nationally protected species, and no nesting hollows will be affected during these safety upgrade works."
Earlier in the day, Kangaroo Island mayor Michael Pengilly was making additional inquiries, with the council staff still unclear about the fate of the trees.
Mr Pengilly said he was adamant he did not want to the trees cut down and would prefer to see measures such as barriers and even a lower speed limit if necessary.
The department is improving safety on approximately 12 kilometres of the Playford Highway, between Birchmore Road and 1.4 kilometres west of Bark Hut Road.
This $1 million safety improvement project forms part of the $104.6 million first tranche of the COVID-19 stimulus Road Safety Package for South Australia, which is jointly funded by the Australian and South Australian governments (80:20).
The upgrade works include shoulder sealing, replacing guide posts and installing audio tactile line marking on the edge lines and centre line.
The audio tactile line marking creates noise and vibration when a vehicle strays from its lane.
Together with shoulder sealing, this improves safety for motorists by reducing the risk of run-off road type crashes.