A Process Trailer, also known as Insert Trailer, or Low Loader is a trailer towed by a Film Tracking Vehicle for the purpose of being used as a moving Camera Platform. They are generally very low to the ground to give a realistic perspective of height and can expand in width to allow the camera to achieve a wider shot.

In Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

they must always be permitted for each individual job and be chaperoned by police