Delhi’s air pollution has once again reached alarming levels, raising concerns that the city may soon move into Stage 4 of the Graded Response Action Plan (GRAP). GRAP acts as a rulebook guiding authorities on the actions required when air quality becomes harmful to public health.
Currently, Stage 3 restrictions are in place across Delhi-NCR, but with the Air Quality Index (AQI) rising sharply, the possibility of triggering GRAP Stage 4 is high.
What Triggers GRAP Stage 4?
Stage 4 is the highest alert level under GRAP and comes into force when the AQI crosses 450, entering the “Severe Plus” category. At this level, the air becomes toxic enough to affect even healthy individuals, increasing the risk of respiratory distress, headaches, and serious health complications. Authorities enforce Stage 4 only when immediate and strong action is required to prevent the situation from becoming a public health emergency.
Strict Curbs on Vehicles and Transport
If Stage 4 is implemented, one of the biggest impacts will be felt on Delhi’s roads. Non-essential trucks will be banned from entering the city, while only vehicles carrying essential goods or running on CNG, LNG, electricity, or BS-VI diesel will be allowed. Commercial vehicles from outside Delhi, except electric, CNG, and BS-VI diesel vehicles, will also be restricted.
Within Delhi, BS-IV and older diesel medium and heavy goods vehicles will not be permitted unless providing essential services. The government may also consider reinstating the odd-even scheme to quickly reduce vehicular load. Public transport services such as the Delhi Metro and buses may be increased to support commuters and avoid overcrowding.
Construction and Industry Shutdown
GRAP Stage 4 mandates a complete ban on construction and demolition activities across Delhi-NCR. This includes major government projects such as flyovers, expressways, and pipelines. Only critical national infrastructure projects, including defence and healthcare, may continue. Stone crushers across the region will also be shut down due to their high dust emissions.
Impact on Schools and Workplaces
To protect children, all physical classes may be suspended, except for students in Classes 10 and 12. Schools may shift to online learning temporarily. Government and private offices could be directed to implement at least 50% work-from-home arrangements to reduce road congestion and emissions.
What Happens Next?
The Commission for Air Quality Management (CAQM) is closely monitoring the situation. Stage 3 restrictions will remain in place until AQI levels show consistent improvement. However, if pollution continues to rise, GRAP Stage 4 will be imposed immediately to control the escalating crisis.
