Safe Routes to Schools programs are an increasingly popular means of addressing parental concerns about traffic safety and encouraging parents to permit their children to walk and bicycle to school. While there has been a good deal of recent research examining the health and physical activity benefits associated with these programs, there has been little systematic examination of the effects these programs may have on the actual safety of child pedestrians. This paper summarizes the existing empirical evidence on the behaviors known to lead to crashes involving child pedestrians, as well as the effects that 10 safety countermeasures commonly incorporated into Safe Routes to Schools programs have on both the incidence of crashes involving child pedestrians and the behaviors known to result in such crashes. The paper finds that many safety benefits associated with these countermeasures are assumed rather than known and that there are substantial gaps in the existing knowledge about the specific safety effects of the components of Safe Routes to Schools programs. It concludes by identifying opportunity areas for future research on this important topic.