Cities worldwide can save thousands of lives every year through fairly simple measures: traffic calming and speed management. Readjusting vehicle speed limits on urban roads is one of the key initiatives highlighted by the UN and the WHO to help countries meet the target of halving traffic deaths and serious injuries by 2030.

We must slow down traffic in Brazilian cities—and fast. This is a public health issue, as traffic crashes are among the leading causes of death worldwide. It is also a matter of quality of life and equity, as cities that effectively reduce vehicle speeds become safer, more welcoming, and more vibrant for everyone.