Viale Leonardo da Vinci, known as "Declassata", was built in the 30s of the last century and used as the Firenze-Mare motorway. The heavy traffic led soon to realize a new road, the A11 and the former highway became a provincial road. The avenue runs east to west through the Municipality of Prato and is still a focal point for traffic and city life. With the urban development of Prato and the consequent growth of car ownership, the traffic receiving capacity has become insufficient. For this reason, over the years it was necessary to enlarge this road and replace the crossings with underpasses.
Currently almost all the avenue is dual carriageway except for the stretch of road between via Marx and Via Nenni, that is the tangent of the city centre.
The Declassata road plays a role as an east-west connection and due to the urban development outside the historical centre sizes and separates the city. It has the connection function between the "nodes". Failure doubling of such a strategic stretch causes considerable traffic slowdowns in changing from two lanes in each direction to one lane. Completing the enlargement of the roadways can be a prerequisite for the development of the city, to the need of an alternative to the motorway and an excellent connection to the central Italy road-rail distribution hub located in Gonfienti, indispensable for industry and trade in a wide industrial area.