Local government rangers are empowered to stop vehicles under section 38(7) of the Control of Vehicles (Off-road Areas) Act 1978 if they reasonably believe the driver or the vehicle has contravened a provision of that Act. For example, if your committing an offence while driving in your 4x4 in the Gnangara pine forest or a park, beach or similar, then go onto the road, the ranger is empowered to stop you.
Inspectors appointed under the Animal Welfare Act 2002, being RSPCA staff and some regional local government rangers, are empowered under section 39(2)(a) of that Act to stop vehicles suspected of being involved in an offence under that Act.
Fisheries officers cannot
generally stop vehicles, but when they are enforcing provisions relating to cruelty to fish (yes, it exists!) they can use all the powers of an inspector under the Animal Welfare Act 2002, thus can stop vehicles.
I don’t think
customs officers can stop vehicles, although have the power to stop and board boats and aircraft. But I’m not too familiar with Commonwealth law so I may be wrong.
I don’t believe
ACMA have the power to stop vehicles. Once again, not too familiar, so may be wrong.
Inspectors and
authorised persons appointed under the Environmental Protection Act 1986 are empowered to stop vehicles under section 91A(1) of that Act, if they reasonably believe an offence has been, is being, or is going to be committed under that Act in relation to that vehicle.
There are a number of ‘
wardens’ able to be appointed under the Road Traffic Act 1974 that have the power to stop vehicles and/or direct traffic. Some of these wardens are:
Traffic escort wardens – These are the guys that assist in the escort of oversize vehicles. These guys have the power to stop vehicles under section 53 of the Act and can also give directions to drivers under regulation 272 of the Road Traffic Code 2000. They can also give infringement notices for traffic offences.
Crossing attendants – These are the old folks that stand outside schools and help kids cross the road. They have very limited powers to stop traffic so that people can cross the road. They must be wearing their hi vis vest to be able to exercise those powers.
Transport wardens – Main Roads Transport Inspectors, Dept of Transport Taxi Compliance Officers, and Dept of Transport Vehicle Examiners are appointed as transport wardens. They have extensive powers to stop and inspect vehicles, direct traffic, demand name and address, give infringement notices for traffic offences.
FESA fire fighters would be able to direct traffic under the Fire Brigades Act where necessary as they have extensive (pretty much unlimited) power to do anything they believe is necessary to control a fire.
Department of Environment and Conservation rangers (i.e. park rangers) and land management officers are empowered under section 124(1)(a) of the Conservation and Land Management Act to stop and detain vehicles suspected of being involved in an offence under that Act.
Dangerous Goods Officers appointed under the Dangerous Goods Safety Act are empowered to stop vehicles they suspect may be carrying dangerous goods. Although Main Roads Transport Inspectors enforce this Act under an agreement with the Dept of Mines and Petroleum.
Most security officers at universities are empowered under the university’s by-laws to direct traffic, but only within the grounds of the university. I know Murdoch Univeristy security officers used to fine people for speeding through the university.
Many other government facilities such as hospitals and the parliamentary reserve have by-laws which may give power to ‘authorised persons’ (usually security) to direct traffic within the confines of their respective facility.
There may even be a lot more people with the power to stop vehicles that I’m not aware of.
But I think the only people that you would get stopped by are police or transport inspectors. I don’t think the others, although empowered to do so, really exercise those powers, or even have the equipment to do so (magenta lights on their vehicles etc).
With regards to the yellow sticker on the prime mover thing. I can almost guarantee that a prime mover has never been issued a yellow sticker (defect notice/compliance notice) by a transport inspector for a defect on a trailer that it’s towing. Once exception, maybe, is the lights weren’t working on the trailer and the inspector believed the defect was actually in the cabling (or some other component) in the prime mover, not on the trailer.
Hope this info has been helpful in answering your question