Assessing traffic emissions during the summer world university games 2023: Insights for multisectoral synergetic decontamination.

Implementing temporary traffic control measures is a common strategy to prevent air pollution and alleviate traffic congestion during mega-events. Accurate assessment of event-time vehicular emissions is useful for local authorities to develop effective policies. However, many previous assessments were based on policy-based scenarios, which often failed to capture the synergistic impact from other sectors (e.g., the industrial sector). Here, we conducted both traditional scenario-based ex-ante evaluation and data-driven real-time emissions tracking to evaluate the impacts of traffic restriction policies during the Summer World University Games 2023 in Chengdu, China. Real-time tracking revealed that average vehicle kilometers traveled (VKT), traffic emissions of nitrogen oxides (NOX), and volatile organic compound (VOC) decreased by 18.3 %, 37.9 %, and 18.4 %, respectively, compared to the non-event period. The scenario-based ex-ante evaluation substantially underestimated NOX emission reduction from the truck fleet due to the lack of consideration for multisectoral synergistic effects. Event-time interventions in the industrial sector accounted for an additional 18.1 % reduction in truck NOX emissions. This study underscores the importance of considering cross-sectoral synergy when establishing policies for future mega events.