The speed limit changes will be on the Princes Highway at Tomerong and Stringybark Road at Nowra Hill.

The Princes Highway speed limit from 500 metres north of Island Point Road at Tomerong to 840 metres north of Sussex Inlet Road is being reduced from 100 km/h to 80 km/h.

A Transport for NSW spokesperson said a speed zone review was undertaken on this length of highway in response to safety concerns and a high casualty rate.

"The review also took into account the safety improvements nearing completion at the Princes Highway and Island Point Road intersection," the spokesperson said.

"The change in speed limit will align with the speed through the new intersection, providing road users with a stretch of about nine kilometres of the highway at 80km/h."

Transport for NSW carried out the review in accordance with the NSW Speed Zoning Guidelines, which considered a number of factors including roadside development, traffic data and crash history.

"The change in speed limit will address immediate safety issues on this section of the highway while planning of the highway upgrade between Jervis Bay Road and Sussex Inlet Road continues," the spokesperson said.

"Cardo (NSW/ACT) Pty Ltd is on board to help Transport for NSW identify a preferred strategic option for this section of the highway upgrade and more information on the project will be available later this year.

"The upgrade would better connect regional centres, deliver a more resilient transport network, improve safety, ease traffic congestion and support the growth of regional economies."

Work as part of the speed limit reduction will take place between 7am and 5pm on Friday, November 6, with traffic control and a reduced speed limit in place for the safety of motorists and workers.

The speed limit on Stringybark Road at Nowra Hill will be reduced from the first Tuesday in November with the existing 100 km/h speed limit lowered to 60 km/h for the entire length of Stringybark Road.

Again Transport for NSW completed a speed zone review following a request by local residents and in consultation with local council and police.

"This change is being due to the road environment - in particular its narrow width - and a lower speed limit will result in improved road user safety," the spokesperson said.

New speed limit signs on Stringybark Road will be installed between 7am and 5pm from Tuesday, November 3, weather permitting, with traffic control and a reduced speed limit in place for the safety of motorists and workers.

Temporary signs will be in place for one week before and after the speed limit reduction to alert motorists of the change.

Motorists are asked to keep to the displayed speed limit for the safety of all road users.

Members of the community can sign up at the Safer Roads NSW website to receive updates about changes to permanent speed limits in their area and to have a say on speed limits.

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