Building yards, excavations, machinery and machine operators must be fenced in at all times, in particular in areas where vehicles or people pass, to ensure their safety by means of barriers, railings and other types of fencing. Once it was simply habit to fence off construction sites, but now Legislative Degree 493/996 has established that indicators must be used “when risk cannot be avoided or sufficiently reduced with technical means of protection or with measures, systems or work organisation methods”. Furthermore, the technical specifications regarding indicator plans, published in 2002 by the Minister for Infrastructure and Transport, states that barriers which are compulsory in dangerous zones “can be replaced with fixed red or orange fencing that can include textiles, netting or other means of enclosure approved by the Minister for Infrastructure and Transport”.