Rules for trailers and vehicle combinations

In a built-up area, do not leave a trailer parked while detached unless signs permit it. While coupled and in use it is covered by the towing vehicle's policy, whereas a detached trailer needs static-risk cover. A trailer must be registered and have its own registration plate; it does not become an integral part of the towing vehicle and the towing vehicle's plate is not moved onto it. Technical towing limits include the ratios tested in the questions: up to 1 for a braked trailer not exceeding 3.5 tonnes and 0.5 for an unbraked trailer. Remove, fold or retract an unused detachable towbar if it projects beyond the vehicle outline. Additional external mirrors must not project by more than 20 centimetres beyond the widest point of the combination. Italian T.A.T.S. trailers carry leisure equipment that is not intended for sale. On a motorway with at least three lanes, a combination over seven metres long may use only the two rightmost lanes. Drivers of combinations over 3.5 tonnes are subject to a zero blood-alcohol limit.