Longitudinal Analyses of Washington State Student Travel Surveys

Abstract

Part of a long-term collaboration between the University of Washington (UW) and Washington State Department of Transportation (WSDOT), this project contained two studies: (1) longitudinal changes in active school transport (AST) rates and (2) impacts of Safe Routes to School (SRTS) projects on AST rates. (1) The average rate of AST for the 241 schools surveyed in 2016 was 21.2 percent, compared to 14.1 percent for the 198 schools surveyed in 2019. The difference in rates was explained primarily by the difference in the schools sampled in the two waves. For the 32 schools that were included in both surveys, rates were similar at 22.3 percent in 2016 and 19.8 percent in 2019. Schools included in only the 2019 survey lacked characteristics that are known to be associated with higher rates of AST: their neighborhood had lower street connectivity; they offered less encouragement for AST; their students were younger; and a higher proportion of them lived farther from school. Differences in walkability scores and walking potential scores between the two waves further confirmed these findings. (2) Evaluating the association between rates of AST and SRTS project awards was based on 94 projects with complete project information from multiple databases. Most projects (N=53) were accompanied with increases in students walking to/from school; 40 had increases in the number of students biking. For other projects, decreases were observed (N=17 for walking; N=18 for biking). On average, schools with SRTS projects had a 33 percent increase in the number of students walking and a 104 percent increase the number of students biking. Regarding project type (with primarily an engineering, education, or enforcement component), larger effects were found for education projects (17 percent and 37 percent increases in walking and biking, respectively) and enforcement projects (2 percent and 115 percent increases in walking and biking). However, these findings have limited generalizability because of the small sample size (N=32).