A day after the Commission for Air Quality Management (CAQM) notified stage four of the Graded Response Action Plan (GRAP), there was little noticeable improvement in Delhi’s air quality, with the air quality index, or AQI, exceeding 450 this week. In this regard, the Supreme Court rightly flagged the delay in implementing pollution preventive measures. GRAP-4 includes a ban on entry of truck traffic into Delhi, a strict ban on plying Delhi-registered BS-IV and below diesel-operated medium goods vehicles and heavy goods vehicles, a temporary halt in construction and demolition activities, discontinuing physical classes in educational institutions, and an option