Police would keep the stretch under surveillance.
The limit will take in the stretch from the airport to south of Meeanee Quay.
"This section is well known to local drivers and includes some of the more challenging road features of a state highway," Mr Postings said.
"Given the influx of visitors into the region over the summer period the Transport Agency and police believe that a temporary speed limit reduction will be an effective means of improving safety on this section of highway for the summer season when many visiting drivers will be using the road."
The agency also has long-term plans for continuing to increase safety on the stretch.
"Safety improvements for these intersections will be addressed as part of work on the whole section of road to be carried out in late 2016 or early 2017," Mr Postings said.
"During construction this section will be under traffic management for some months, and the temporary restriction this season will set the scene for motorists over the next summer season as further improvements are made."