With the increasing demands of traffic, it is more and more frequently necessary to widen roads motorways and rail tracks to increase their capacity. The problem becomes difficult if not impossible when the routes run through tunnels unless resort is made to costly additional routes with the creation of new tunnel arches to add to the existing ones.

Rocksoil S.p.A. has researched and developed special new technology which by making judicious use of the "active arch" principle and modern conservation systems, allows routes to be widened and all works to be carried out while traffic runs in safety under a protective "steel shell".

This technology was employed to widen the "Nazzano" tunnel, on the Rome to Naples motorway, from two to four lanes in each direction. Particular features include its extreme versatility, since it can be employed in a great variety of ground and stress-strain conditions and the high degree of mechanisation of works that can be achieved with a consequent regular rhythm of tunnel advance and reduction in construction times, all factors with positive repercussions on site budgets and advance rates.

Following the success in Nazzano, the new technology is now applying for enlargement in the presence of traffic of the ''Montedomini'' tunnel (Motorway A14, near Senigallia).