A4, fourth dynamic lane

Viale Certosa Sesto San Giovanni

€ 240
million
to be invested
€ 10
km
of fourth dynamic lane in total
1,5
tonnes
of CO2 saved each hour when activate
mappa
video

Description of the project

The project involves the creation of a fourth dynamic lane on a 10-km section of the A4 Turin-Trieste motorway, between the Viale Certosa and Sesto San Giovanni junctions. This section registers peak traffic flows of approximately 200,000 vehicles a day in both directions, with hourly peaks of approximately 6,000 vehicles in each direction.

Given the impossibility of widening the carriageways, due to their close proximity to urban areas, the response to the need to boost capacity on the section consists of the temporary use of the hard shoulder as a fourth running lane. This will be opened/closed to traffic based on a smart system for continuously monitoring traffic flows on the section involved.

The aim is to ensure improved traffic flow through the application of innovation and technology, thereby increasing the capacity of the infrastructure, and generating benefits in terms of environmental impact: for every hour the fourth dynamic lane is active on the approximately 10-km section, it is estimated that approximately 1.5 tonnes of CO2 will be saved.

In July 2023, the first section of lane between the Viale Certosa and Cormano junctions, amounting to approximately 3 km, opened to traffic in both directions.

The technology platform, developed by MOVYON, enables the available hard shoulder to be used temporarily by traffic under certain specific conditions on the section, measured through the processing of data obtained from sensors, the use of algorithms and traffic flow forecasts.

The programme ensures coordinated management of:

  • traffic assessment through sensors along the motorway
  • notification of the change in use of the lane and speed limits to road users.

An Automatic Incident Detection (AID) system detects incidents that may potentially put traffic at risk, such as vehicles that have stopped on the dynamic lane, vehicles heading the wrong way, tailbacks.

The occurrence of any one of these events is notified in real time to operators in the radio control room and the hard shoulder is closed to traffic. Monitoring is conducted by radar, laser scanners and cameras equipped with AI algorithms that continuously scan the carriageways and traffic.

The second section, running continuously with the first through to the Lambro service area, is due to enter service at the end of 2023, whilst installation along the entire section is due to be completed by the end of 2024.

Community initiatives

Completed initiatives, financed and designed by Autostrade per l'Italia, include:

  • construction of a 500-metre long noise reduction tunnel in the municipality of Cinisello Balsamo to mitigate motorway traffic noise, and construction of a public square above the motorway tunnel to connect the Crocetta district with Matteotti Park;
  • the upgrade of Via Torino, between the municipalities of Cormano and Novate Milanese;
  • construction of a new railway overpass to replace the existing one.

The following are also nearing completion:

  • the upgrade of the “Marianella” motorway underpass that is to become a cycleway and footpath;
  • construction of approximately 10.5 km of new noise barriers.