Drivers are being urged to take extra care on the roads as farm machinery and trucks mobilise for a big harvest across regional NSW.

Council's' Road Safety and Injury Prevention Officer, Melanie Suitor, said the bumper harvest will mean there will be more trucks and slow-moving farm machinery on the roads as well as a surge in activity on level crossings where trains are not often seen.

“It’s looking like this harvest is going to be one of the biggest we have had in our region for a number of years," she said.

"We need to remember how busy our local roads are during harvest.

"If you see a vehicle displaying an oversize sign, the vehicle will be wider, longer or higher than a normal vehicle.

"They may also be accompanied by a pilot vehicle with flashing lights and warning signs.

“When approaching an oversize vehicle you should: be patient, reduce your speed and wait for a safe opportunity to pass.

"Remember if you can't see the vehicle's mirrors, chances are they can't see you."

An awareness campaign run by Forbes, Parkes and Lachlan councils in partnership with Transport for NSW is promoting sharing the road safely this harvest with fold down grain truck warning signs positioned along key harvest routes and at silos along with a radio campaign to remind drivers what to do when they encounter farm machinery on the road.

Ms Suitor is also reminding drivers that harvest will see increased train movements on lines where they may not often be seen.

"Please obey the signage and stop and check for trains at level crossings this harvest," Ms Suitor said.

Farmers and grain transporters are also reminded to manage their fatigue after long days harvesting and transporting grain.

"Fatigue is one of the biggest killers on our roads," Ms Suitor said.

"We ask those involved in harvest to ensure you are well rested and if you feel tired while driving, pull over in a safe place and have a rest. We want everyone to get home safely this harvest."