Rapidly growing megacities face the challenge of sustaining economic activity without exacerbating air pollution. This study examines Jakarta, Indonesia, to identify the specific traffic behaviors and time periods that offer the greatest potential for reducing pollution with minimal economic impact. Using a full year (2023) of traffic counts, air-quality measurements, and weather data from the city’s central business district, we constructed an Economic Activity Index and calculated the pollution intensity to measure emissions per unit of economic activity. Cluster analysis was applied to categorize hourly conditions into distinct traffic–pollution patterns.

Results reveal a four-hour lag between peak traffic volume (17:00) and peak PM2.5 concentration (13:00), indicating substantial pollution buildup. Heavy vehicles generated disproportionately high PM2.5 intensity, particularly in evening hours, while midday periods dominated by motorcycle traffic produced unexpectedly elevated pollution levels. Six characteristic traffic–pollution patterns emerged, with the “Congested Midday Mix” representing the most polluting condition. The association between economic activity and pollution was present but weaker than anticipated, suggesting meaningful opportunities for policy intervention.

The findings demonstrate that economic productivity and air pollution can be partially decoupled through targeted strategies. Recommendations include shifting heavy-vehicle freight to nighttime; accelerating the electrification of motorcycles and buses, especially for midday trips; and applying real-time traffic management during high-pollution periods. This framework offers an evidence-based pathway for megacities seeking to balance economic growth with cleaner and more sustainable urban mobility.