Accidents involving young pedestrians often have consequences which are both serious and expensive. One of the important factors involved in reconstructing these accidents is the speed of the pedestrian. There are limited data on the walking and running speeds of children but they are related to age and sex. Young children of any given age can vary substantially in height and weight, and this can influence their walking and running speeds.In some instances, the children move from a standing start only a short distance to the point of collision. In these cases, their acceleration is at least as important as their steady speeds. Little data on the acceleration of children are available.A study has been conducted of elementary school children to measure their acceleration characteristics, walking speeds and running speeds. Accelerations and speeds related to pedestrians’ age, sex, height and weight have been documented. Empirical formulae have been developed for various combinations of these variables. Implications for accident reconstruction are discussed.