The move followed Main Roads indicating to some farmers who applied for vehicle movement permits in readiness for the season, it would not issue permits for some brands of four-wheeled air seeders to travel across or on public roads because the axle loading weight exceeded 14 tonnes per axle, the maximum permitted under specific circumstances to avoid potential damage to roads.
At the WAFarmers' annual general meeting last week, part of its 2019 Trending Ag conference, members successfully moved that "WAFarmers advise Main Roads that the current regulations for the movement of agricultural machinery in WA are unacceptable to industry".
"WAFarmers calls on Main Roads to put in place an amnesty of prosecutions for oversized seeding equipment for 2019 and work with the industry to assist in drafting new requirements to accommodate modern equipment," it said.
The motion followed an earlier conference discussion where frustrated farmers told Main Roads WA heavy vehicle technical officer Peter Lewis, a guest speaker last Thursday, they could not get permits to move some airseeders from paddock to paddock or between properties if they have to cross or travel on public roads.
Mr Lewis said he was aware of some weights of up to 17 tonnes per axle with a particular brand of seeder which meant the equipment could not be driven or towed on public roads under any circumstances.
"These things are designed for off-road use, they can't exceed the maximum weight limits for the number of tyres and the size of tyres," Mr Lewis said.
"Fourteen tonnes at this time is the absolute maximum for a single axle.
"Impact studies are being done comparing agriculture tyres to road tyres and we are waiting for the results of those to come back.
"Unfortunately this will limit what can come onto the road in the meantime," he said.
Mr Lewis said to achieve the maximum 14 tonnes axle loading, four tyres per axle were required.
With only two tyres per axle, nine tonnes was the limit under amended restricted access agriculture machine regulations introduced last month.
These amendments increased the maximum width of agricultural equipment able to be moved on public roads without a permit and with accompanying agricultural heavy vehicle pilots rather than accredited licenced heavy vehicle pilots from six metres to 7.5 metres.
"We've got machines out there, primarily airseeders, that we can't get permits for," one farmer told Mr Lewis.
"We congratulate you on the changes that have been made, but they don't go far enough.
"We've got crops to put in this year, we need regulations that are fit for purpose.
"Ours will be going down the road one way or another," he said.
WAFarmers Esperance and Ravensthorpe zone president Matthew Hill said many farmers were under the impression WAFarmers had already negotiated approval with Main Roads WA to allow these machines to be moved on public roads.
He said he believed the scope of the amended regulations had not been conveyed to farmers very well.
In some circumstances they can only travel one kilometre without a permit on a State road under the amended regulations with up to three agriculture heavy-vehicle pilots, but this was not widely known, another farmer pointed out.
If they wanted to go half a kilometre further on a State road before they turned off onto a local road or into a paddock, they had to apply for an over-size or over-mass agricultural vehicle movement permit and at least one of the pilots had to be an accredited licenced heavy-vehicle pilot, he pointed out.
Mr Lewis told farmers changes in 2017 and last month in conjunction with the Department of Transport (DoT) to regulations as a result of approaches by WAFarmers had relaxed some requirements in relation to over-size and over-mass agricultural vehicles and access to rural roads without a permit provided certain criteria were complied with.
Drivers of pilot vehicles accompanying some agricultural heavy vehicles no longer needed to be licenced heavy vehicle pilots if they are travelling less than 100 kilometres on local shire roads and less than a kilometre on State roads, he said.
Rubber tracked vehicles, previously not permitted on public roads, can now travel provided they have tracks a minimum of 406 millimetres wide and maximum weight of 14 tonnes per track for twin-track machines and seven tonnes per track for quad-tracks and half-track machines.
Mr Lewis said Main Roads and DoT came up with "appropriate exemptions" from regulations that previously prohibited rubber tracked vehicles using public roads.
He said exemptions were available from DoT when farmers registered their vehicle.
Maximum size for wheeled or tracked agricultural vehicles not requiring a vehicle movement permit under certain circumstances are six metres high, 12.5m long, 7.5m wide and with a gross vehicle mass (GVM) of 28 tonnes.
Whether one, two or three pilots in appropriately signed vehicles fitted with flashing lights needed to accompany an agricultural machine on public roads is determined by the size of the machine.
Mr Lewis said twin-steer load-sharing axle group weights, primarily on some prime movers hauling grain trailers, had also been increased.
Up to 12t on the steer axles was now allowed on vehicles with a GVM of 22.5t or more, provided tyres were at least 375mm wide and no manufacturers' ratings were exceeded.
"(The change is) one step further than previous which set a maximum combination GVM of 42.5t, which meant that if you were slightly heavier on the steer axles you lost carrying capacity because you couldn't exceed 42.5t," Mr Lewis said.
"With this new exemption, the additional mass you're allowed on the steer axles is added to the allowed combination GVM, so if you're allowed 12t it's added to the total combination mass, so anything up to 43.5t without a permit or anything else from Main Roads is allowed," he said.