What is the leading cause of death in Italy among males under 50? It is not smoking, it is not cancer, it is not alcohol. The thing most likely to kill you is a road accident: there are three thousand deaths on the roads every year that go unreported. That is twice the number of victims in the United Kingdom, which has a broadly similar population to Italy's.

Yesterday's accident is one that could hardly pass unnoticed: in Rome, some newly licensed drivers hired an SUV — a vehicle weighing over 2,200 kilograms — to carry out a challenge to be published on their channel The Borderline, on YouTube and TikTok, which involved staying on board the vehicle for 50 hours. While driving — perhaps distracted by the challenge itself or by the filming — they caused a fatal accident, ploughing into a small car carrying a young mother of 29 and her two children aged 4 and 5. The first two were taken to hospital, while the 5-year-old boy died.

Almost everywhere, unanimous condemnation has already been levelled at social media for pushing young people towards pure exhibitionism, as this appears to be one of the causes of the distraction. But we are losing sight of one of the other — perhaps even more serious, widespread and invisible — tragedies at the heart of this story.

Paolo Gandolfi is a former Italian member of parliament, one of the foremost experts in the field of sustainable mobility. He was, among other things, the driving force behind the bill on road homicide and is better placed than anyone — in an Instagram post — to explain the three main causes of death on the roads: "Except in rare cases, what kills is the combination of three factors: wrong behaviour, the car, speed."

In this wonderful country, the debate revolves around indicators on e-scooters, insurance or helmets. But would we really have fewer deaths on the roads if we implemented these measures?

Instead: how many fewer deaths would there be if we designed roads and spaces to the scale of children, the elderly and the most vulnerable? If every city became a Zone 30, and if the most dangerous vehicles — such as cars, sometimes true urban tanks — were structurally and urbanistically forced to comply with safety limits.

About a quarter of the people involved in those three thousand road deaths are in fact people who were moving on foot or by bike. How much more accessible, safer, more tourist-friendly, more spacious, more humane, more sustainable would our roads become? A wonderful advertisement asked a young man on the street what the acceptable number of deaths in the city was. The year before, there had been 213. In his view, the acceptable number was 70. Then, from around the corner, 70 people he knew personally were brought out: his family, his friends. And he immediately said: "Zero, zero people."

Zero is the only acceptable number of deaths on the roads.