«One year at 30 km/h»: Bologna changes pace and wins

One year after introducing a 30 km/h speed limit, Bologna evaluates its progress: the decision to slow urban traffic is delivering significant improvements in road safety, sustainable mobility, and environmental quality.

Since January 16, 2024, Bologna has become Italy’s first major city to widely adopt a 30 km/h speed limit across most of its urban streets, officially becoming a “City 30.”

Twelve months on, data clearly demonstrate tangible benefits from the speed reduction: daily traffic has dropped by over 11,000 vehicles; bicycle usage has increased by 10%; bike-sharing services have surged dramatically (+69%); car-sharing use has significantly grown (+44%); and the metropolitan railway service (Sfm) has recorded a 31% increase in passengers. Concurrently, nitrogen dioxide emissions—directly linked to vehicle traffic—have decreased by 29%, supported by concrete infrastructural improvements including new pedestrian squares, expanded cycling paths, and safer pedestrian crossings.

A similar pattern emerges from other successful examples like Brussels, where introducing a reduced speed limit has created a more livable urban environment, with a substantial drop in road accidents, stable travel times, reduced noise pollution, and increased walking and cycling.

These data thus confirm that coordinated policies promoting sustainable mobility—supported and enhanced by appropriate infrastructure, public services, pedestrian spaces, and cycling routes—offer cities a solid foundation to achieve greater safety and an improved quality of life: a proven and effective model for any forward-thinking urban area.