Road unit A road unit, also called an articulated unit, is a vehicle of the heavy-duty family consisting of a tractor and a semi-trailer. The SREM is hitched to the tractor using the fifth wheel. The road combinations are often called "semi-trailers" by abuse of language.
The road set should not be confused with the road train which refers to a vehicle made up of a tractor and several trailers, the circulation of which is not authorized in France.
In most European countries, the maximum length of a road combination is set at 16.50 meters. Since January 1, 2013, an assembly with up to 4 axles has a permissible gross vehicle weight of 38 tonnes. For an assembly with more than 4 axles, the GVWR is increased to 44 tonnes, and the maximum axle load for the most heavily loaded axle must not exceed 12 tonnes. From 6 axles, an additional tonne of loading is granted to compensate for the weight of the sixth axle. The tractor GVWR must be at least 44 tonnes, and the semi-trailer's GVWR can vary from 37 tonnes for 2 axles to 38 tonnes for 3 axles.
The bodywork of road assemblies are the same as those of semi-trailers: tipper, car carrier, sliding curtains, Savoyard, log truck ... Special provisions are planned for exceptional convoys, but also for the transport of round timber: articulated log carriers see their GVWR increased to 48 tonnes if they have 5 axles, and 57 tonnes if they have 6 or more axles. Their length can reach 18.75 meters.
Consult the ads for used articulated sets from the brands Renault, Volvo, Scania, DAF, Iveco, MAN and Mercedes.