Due to the different companies that manage the different parts of the motorway, it is often referred to as formed by five sections: Turin-Milan, Milan-Brescia, Brescia-Padua, Padua-Venice and Venice-Trieste.

As it runs through the whole Pianura Padana, which is a densely populated and highly industrialized area, A4 is one of the most trafficked motorways of Italy.

Before World War II, three sections of the motorway were built: Turin-Milan, Milan-Brescia and Padua-Venice.

The objective of the route is to reduce the volume of auto- and truck-based traffic passing through Mestre (a mainland frazione of Venice) to reach non-local destinations like Austria, Slovenia and other Eastern European countries.

Autostrada A4 Passes through Turin, Settimo Torinese, Novara, Cusano Milanino, Cinisello Balsamo, Monza, Bergamo, Brescia, Verona, Vicenza, and Padua.