Objectives To quantitatively describe the recent longitudinal trend in road injuries involving school children while commuting to and from school in Japan and to identify groups or situations with particularly large or small decreasing trends.

Methods Data on the number of children aged 6–15 years who sustained road injuries while commuting were obtained, stratified by year, demographic characteristics, mode of transport and other variables. The rates of killed or seriously injured (KSI) children were calculated from the number of KSI cases (the numerator) and the product of population and the proportion of each mode of transport estimated using the Person Trip Survey data (the denominator). We conducted descriptive analyses of the longitudinal trend in KSI rates stratified by the variables, and Poisson regression analyses were employed to quantify the annualised changes in the rates.

Results During the study period, 166 children were killed and 8484 children were seriously injured; the KSI rate decreased approximately 30%. The KSI rate was almost 10 times higher among cyclists than pedestrians. In cyclists, the decrease in the KSI rate among children aged 12–15 years was smaller in boys than in girls (estimated change −14% vs −30%). The KSI rate of male pedestrians aged 6–7 years was larger than female and older pedestrians, with a large decrease of 48%.

Conclusions Although the overall rate of road injuries among children while commuting was decreasing, cyclists were at a much greater risk than pedestrians, and the improvements for cyclists occurred at a slower pace.