Evaluating the impact of a School Streets intervention on personal vehicle use and air quality: Pilot studies at four suburban schools in Canada

Active School Transportation (AST) has declined globally, coinciding with increased personal vehicle use. School Streets interventions aim to reverse this trend by temporarily closing streets adjacent to schools during drop-off and pick-up times to promote AST and reduce vehicle use while offering additional benefits like improved air quality. While grey literature suggests effectiveness, rigorous evaluations are lacking. This study examined School Streets at four suburban schools in two Canadian cities, where implementation strategies differed. Changes in personal vehicle use were assessed through vehicle counts, while traffic, emissions, and dispersion models estimated fluctuations in vehicle emissions and related ambient air pollution. Results showed School Streets reduced personal vehicle use by 35 %, vehicle emissions by 31 %, and related ambient air pollution by 93 %. However, post-intervention reductions fell to 5 %, suggesting that the benefits are primarily constrained to the days when School Streets are active. Effectiveness varied by implementation strategy. In the city where a cross-disciplinary team was involved, benefits were greater, suggesting broader stakeholder engagement may enhance impact. In the city where the school board led implementation, effects were more sustained, highlighting the value of school-driven leadership. Afternoon-only interventions were less effective in the morning but equally or more effective in the afternoon. Closing only drop-off and pick-up areas was less impactful than restricting a larger street section. Morning reductions were larger, likely due to higher initial vehicle volumes, while afternoon reductions were more sustainable, likely reflecting students’ increased likelihood of walking home. These findings highlight School Streets' potential to reduce vehicle use and emissions, emphasizing the need for strategic implementation and stakeholder involvement. • School Streets reduced vehicle use by 35 %, vehicle emissions by 31 %, and related ambient air pollution by 93 %. • Post-intervention reductions in vehicle use, emissions, and air pollution were more modest (5 %). • Greater benefits were observed with cross-disciplinary teams, highlighting the value of broad stakeholder involvement. • Interventions led by school boards showed more sustained effects, emphasizing the importance of school-driven leadership. • Morning reductions in vehicle use were larger, while afternoon reductions were more sustainable.