Delhi chokes: AQI crosses 400; why is GRAP 3 not yet enforced?

Delhi’s air quality has entered the ‘red zone’ with AQI crossing 400, making it the country’s second most polluted city. Despite hazardous levels in several areas, Graded Response Action Plan (GRAP) Stage 3 has not been enforced due to comparatively better air quality this November than last year, attributed to coordinated pollution control measures.