Roads & Motorways

Alternative route to Cisano BG

A new route on the former S.S. 639 ‘dei Laghi di Pusiano e Garlate’ to cross the residential area of Cisano Bergamasco
Owner/client Province of Bergamo
Type of service Final Design; Environmental Impact Assessment; Safety Coordination Design
Location Cisano Bergamasco
Period 2008 - 2014
Cost € 34.974.000

An alternative route to the S.S. 639 and the S.S. 342 crossing the residential area of Cisano Bergamasco with the purpose to reduce transiting traffic.

The new route is an integral part of the larger road development project named 'Collegamento Lecco-Bergamo', which is approx. 23 km long. In synergy with the Pedemontano and Dorsale dell'Isola road system, this route is a key element for the local infrastructural reorganization, aimed at managing the link roads between Lecco and Bergamo, and at facilitating exchanges between this route, the Pedemontano road system and the A4 motorway.

The new route under examination (type C1 road) has a total length of 3,430 m, of which: 1,500 m in embankment, 1,130 m in a cutting, 100 m on a bridge and viaduct and 700 m in an artificial tunnel.

The most significant works are the bridge over the Sonna torrent (mixed steel/concrete structure deck, with a single span of 45 m with a curvilinear axis) and a box-shaped artificial tunnel made of conventional cast-in-place reinforced concrete.

Bridge on Sonna creek

46 meters long (single span), 220 meters bending radius, steel/concrete structure, 14.75 meters wide

'Cisano' tunnel

640 meters long, 14 meters wide, with emergency exit, technical rooms and fire system

'Tre Fontane' tunnel

55 meters long, 12.63÷15.19 meters wide

'Colombera street' underpass

Box section, 14.6 meters long, 10 meters wide

The project pays special attention to the following issues:

1) Road safety and functionality;

2) Tunnel safety (routine and emergency management);

3) Connections with the existing road network;

4) Setting up of building yards and relevant executive phases, in order not to penalize the functionality of the crossing roads;

5) Soil balancing, with lime soil stabilization, thanks to which it is possible to use the excavated material again for road embankments;

6) Landscape and environment, with a special focus on the protection of surface and underground water, sound insulation and landscape setting (a large part of the route crosses the 'Parco Adda Nord').

The main works of art are represented by the bridge over the Sonna torrent (mixed steel/concrete structure deck, with a single span of 45 m with a curvilinear axis) and by an artificial tunnel with a box structure in ordinary reinforced concrete cast in situ.