The school commute is a prime opportunity to increase children's physical activity levels. However,active commuting has decreased over the past 40 years. Strategies that increase walking to school are thereforeneeded. Travelling Green (TG) is a school-based active travel resource aimed at increasing children's walking toschool. The resource consists of a curriculum-based program of lessons and goal setting activities. A previous studyfound that children who received the TG intervention increased self-reported distance travelled to school by activemodes and reduced the distance travelled by inactive modes. This study was limited by self-reported outcomemeasures, a small sample, and no follow-up measures. A more robust evaluation of TG is required to address theselimitations. This paper describes the rationale and methods for such an evaluation of Travelling Green, anddescribes the piloting of various active commuting measures in primary school children.Methods/Design: Measures of active commuting were piloted in a sample of 26 children (aged 8-9 years) overone school week. These measures were subsequently used in an 18-month quasi-experimental design to evaluatethe effect of TG on commuting behaviour. Participants were 166 children (60% male) aged 8-9 years from 5primary schools. Two schools (n = 79 children) received TG in September/October 2009. Three schools (n = 87children) acted as a comparison group, and subsequently received TG at a later date. Physical activity wasmeasured using Actigraph GT1M accelerometers. Personal and environmental determinants of active commutingwere measured via parent and child questionnaires, as were factors related to the Theory of Planned Behaviourand the construct of habit. Measures were taken pre- and post-intervention and at 5 and 12 months follow-up.Discussion: The piloted protocol was practical and feasible and piloted measures were reliable and valid. All studydata, including 5 and 12 month follow-up, have been collected and processed. Data analysis is ongoing. Resultswill indicate whether TG successfully increases active commuting in a sample of Scottish school children and willinform future efforts in school active travel promotion.