A criterion method for measuring route distance in physically active commuting.

PURPOSE: There is a need for accurate, reliable, and feasible methods for determining route distances in physically active transportation. The aim of this study, therefore, was to scrutinize if distances of commuting routes drawn by physically active commuters and measured with a digital curvimetric distance measurement device could serve such a purpose.
METHODS: Participants were recruited when walking or bicycling in the inner urban area of Stockholm, Sweden. Questionnaires and individually adjusted maps were sent twice to the participants (n = 133). Commuting routes from home to work were drawn on the maps. These were measured using a digital curvimetric distance measurer that was carefully controlled for validity and reproducibility. Marked points of origin and destination were checked for validity and reproducibility using stated addresses and address geocoding systems. Nineteen participants were followed with a global positioning system (GPS) to control for validity of drawn routes. An analysis of the effect on distance measurements of any deviations between GPS route tracings and drawn routes was undertaken.
RESULTS: No order effects were noted on distance measurements, and the test-retest intraclass correlation coefficient was 0.999 (P <or= 0.001). The map markings of route origins and destinations were accurate and reproducible. GPS tracings of actual commuting routes taken (n = 19) as displayed in six cases had slight deviations from the routes drawn by the commuters on maps. However, these deviations played an insubstantial role (0.4%) for the distances measured.
CONCLUSION: When physically active commuters draw their commuting routes on maps, they create a valid and reproducible basis for route distance measurements. In combination with an accurate digital curvimetric distance-measuring device, a potential criterion method for measuring the commuting route distance is established.