The Commission for Air Quality Management (CAQM) has reimposed Stage-IV of the Graded Response Action Plan (GRAP-4) across the entire Delhi-National Capital Region (NCR) with immediate effect, starting January 17, 2026. This decision comes as the region's air quality significantly deteriorated, with Delhi's Air Quality Index (AQI) recorded at 400 at 4 PM on Saturday and rising to 428 by 8 PM, bordering the 'Severe+' category (AQI > 450). Under the stringent GRAP-4 measures, several restrictions have been activated. All petrol, diesel, and CNG outlets in Delhi are mandated to supply fuel only to vehicles possessing a valid Pollution Under Control Certificate (PUCC), with penalties for non-compliance. The entry of motor vehicles registered outside Delhi and not conforming to BS-VI emission norms is prohibited from operating within the capital, though exemptions are made for CNG- or electric-powered vehicles, public transport, and those providing essential services. A complete ban has been enforced on all non-essential truck traffic entering Delhi, with exceptions for vehicles carrying essential goods or services, or those running on cleaner fuels like LNG, CNG, electric, or BS-VI diesel. Furthermore, all construction and demolition activities, including linear public projects such as highways, roads, and power transmission lines, are entirely halted. For offices, the CAQM has recommended that public, municipal, and private establishments operate with at least 50% of their staff working from home, potentially introducing staggered timings to reduce peak-hour traffic. Educational institutions in the NCR, including the Government of National Capital Territory of Delhi (GNCTD), may consider shifting physical classes for students from classes VI to IX and XI to an online mode, with classes X and XII often being exempted to minimize disruption to board exam preparations. These measures are proactive steps to prevent further deterioration of air quality and protect public health in the region.