THE NSW Government will be trialling changes to parking in two Pacific Highway rest areas in northern NSW to ensure spaces are available for all drivers to rest and manage their fatigue.

Changes will include the enforcement of fines for light vehicles parked in heavy vehicle spaces and four-hour timed restrictions for light vehicle drivers.

Transport for NSW acting director northern Vicky Sisson said rest areas are provided to improve road safety and reduce the risk of fatigue for all drivers.

"Heavy vehicle drivers are required by law to take mandatory rest breaks, and because of their size are limited to where they can travel, so it is important that heavy vehicle drivers are able to access dedicated parking spaces to manage their fatigue," Ms Sisson said.

Rest area parking restrictions have been introduced in two locations on the Pacific Highway - Yelgun rest area, north of Brunswick Heads, and Arrawarra rest area, north of Coffs Harbour.

"Light vehicles (passenger and commercial vehicles less than 12 tonnes) will not be permitted to park in heavy vehicle spaces in these two locations and penalties will apply", Ms Sisson said.

"A four hour parking limit will also be trialled in the general vehicle parking spaces. This time limit allows adequate time for light vehicle motorists to rest.

"We want everyone to remember that rest areas are a shared facility - this trial aims to accommodate the needs of all road users and help everyone on the road manage their fatigue.

"We encourage all drivers to plan their journey and make sure they're well rested before they head off. For longer trips share the driving if possible, and plan regular breaks. If you need to pull over and rest, a short 15 to 20 minute nap works best", Ms Sisson said.

For travellers who are staying in the area for longer than a rest break, there is a wide range of accommodation options in the local area.

The trial will run for six months. Monitoring will be carried out and considered as part of any future roll out.