Variante di Valico base tunnel completed On 21.12.2010 the base tunnel on the Variante di Valico project between Florence and Bologna holed through. It is the largest highway tunnel in Italy with 8.6 km length and 180 sq m section for each carriageway. The project being carried out by Todini Costruzioni Generali (Salini Group) will be completed in 2012. For more click here and visit tunnelbuilder archive it/21. 52/10