This study aimed to evaluate the effectiveness of the Safe Routes to School (SRTS) intervention in Barcelona, Spain, at reducing the number of road traffic collisions and injuries in the school environment. It was a pre-post, quasi-experimental evaluation with a matched comparison group. Road traffic injuries were significantly reduced in the intervention schools-especially among school-age pedestrians-but not in the comparison schools. The SRTS program significantly improved road safety among children. (Am J Public Health. 2023;113(5):495-499. https://doi.org/10.2105/AJPH.2022.307216).