Encompasses the national and cantonal road network as well as other roads open to motorised transport with a minimum carriageways width of 2.80 metres (including private roads closed to general traffic). For lengths of roads in the road network, dual carriageways with a structural separation between traffic travelling in opposite directions (e.g. motorways) are, in principle, counted only once. For cantonal roads and other roads open to motorised transport however, this principle cannot be observed, due to technical reasons related to the survey. For these roads, sections of road with structural separations for the length of each lane are counted separately. In addition, for national roads, only the main network (main road links incl. access roads) is taken into account. Ramps and connecting roads are excluded.
