Qld Government Safe Towing (PDF link below)
https://www.google.com.au/url'sa=t&r...2kPxfSkPvf9AwE
C&P extract.
Legal requirements
To ensure the safety of yourself and other road users, you must abide by the laws governing the towing of trailers. These are:
• the vehicle and trailer must comply with all relevant registration requirements;
• the vehicle and trailer must be in a roadworthy and safe condition;
• all trailers must be fitted with a rear number plate;
• towbars and couplings must not obscure the towing vehicle’s number plate or rear lights when the trailer is not connected;
• towing more than one trailer is prohibited;
• people are not permitted to ride in trailers or caravans; and
• the speed limit for a vehicle towing a trailer is the same as for a normal vehicle.

