largest legal size trailer
Trending Now. Answers. Best Answer: The new national rules state a maximum combined length of tow vehicle and trialer - including outboards, legs etc. of 19 metres. Max trailer length is 12.5 metres so with 1.5 m allowable overhang potentially 14 metres total and 5 metres left for the tow vehicle. Over this length flashing yellow lights, clearance flags, oversize signs and speed restrictions apply.