Reliability and validity of two instruments designed to assess the walking and bicycling suitability of sidewalks and roads

PURPOSE: Public health professionals hypothesize that when community environments provide suitable walking and bicycling conditions, community members will be more active. Measurement indicators and assessment instruments are needed to evaluate suitability. This study determined the reliability and validity of two instruments to assess the suitability of sidewalks for walking and roads for bicycling. METHODS: Two data collectors used walking and bicycling suitability assessment instruments to collect data on 31 road segments. In addition, three transportation experts used a 7-point Likert response system to subjectively evaluate walking and bicycling conditions for the same segments. Intraclass correlations determined the reliability of each assessment instrument and the reliability of the Likert response system. Pearson correlations (research staff assessments with expert assessments) were calculated to determine the criterion-related validity of the suitability measures. RESULTS: Intercoder reliability (intraclass) correlations for the walking and bicycling assessment instruments were r = .79 and .90, respectively. Intercoder reliability of the experts' Likert response system was r = .73 for the walking form and r = .77 for the bicycling form. Criterion-related validity (Pearson) correlations for the walking and bicycling assessment instruments were r = .58 and .62, respectively. CONCLUSION: Although some variables have lower reliability and validity than is ideal, the walking and bicycling suitability assessment instruments appear promising as instruments for community members and professionals to systematically assess key aspects of the physical environment.