The ‘Zone 30’ plan was met with plenty of vocal opposition when it was first rolled out on 1 January 2021. Its critics said it would make the capital’s road congestion even worse and hurt the economy of the entire country.

For the ministers of the Brussels regional government, it was a Herculean feat to get the new speed limit signed into law, especially given the Byzantine nature of Belgium’s commune and municipality system, which requires a lot of people all agreeing on the same thing.

Indeed, Brussels transport minister Elke Van den Brandt quips that one commune towards the east of the city was opposed to the speed limit plan until they realised that every other area had signed up to it. Its residents quickly changed their tune.

Brussels-Mobility, the city’s public works department, has now published a study that delves into some hard data and shows that the Zone 30’s advocates were right about a lot of the benefits they predicted.

Road deaths were...