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Possibly a good way to lose said trailer.
You can park a semi on the side of the road (within reason) here in SA and being the nanny state it is I would be surprised if you couldn't do it in Victoria.
Don't know about Vic rules, but so long as it's registered, and therefore road taxes have been paid, I don't think there's much you can do about it unfortunately. Although possibly in a dangerous position, technically it's probably legally parked.