New Delhi, Nov. 10 -- With vehicular emissions emerging as a growing contributor to Delhi-NCR's deteriorating air quality even as incidents of stubble burning have declined, the Supreme Court has called for "urgent and immediate intervention", directing Delhi and three neighbouring states to explain how they regulate the entry and movement of vehicles, enforce emission standards and keep overage and polluting vehicles off the roads. In an order released on Sunday, a bench comprising Chief Justice of India Surya Kant and justices Joymalya Bagchi and V Mohana asked the Municipal Corporation of Delhi (MCD), the Delhi government, Delhi Police's traffic department, and the governments of Haryana, Rajasthan and Uttar Pradesh to file detailed responses on the regulatory framework governing commercial and non-commercial vehicles operating within the national capital and the wider National Capital Region (NCR). The court specifically directed the authorities to disclose the mechanisms in place to identify and regulate vehicles that do not conform to prescribed emission standards, including enforcement of Pollution Under Control (PUC) certification requirements, and the steps taken to prevent the entry and operation of overage, end-of-life and otherwise non-compliant vehicles. It also sought figures on the number of vehicles inspected, challaned, denied entry or otherwise proceeded against for violations, besides details of coordination between Delhi and neighbouring states to regulate inter-state vehicular movement. The authorities have also been asked to spell out further short-term and long-term measures to curb vehicular emissions, along with a time-bound roadmap for strengthening enforcement. To be sure, in a report submitted to the court earlier this year, the Commission for Air Quality Management (CAQM) had identified vehicular emissions as the single-largest source of air pollution in NCR, accounting for 23% of pollution in winter and 19% in summer. The latest intervention follows an assessment of compliance with the Grap, placed before the court by amicus curiae and senior advocate Aparajita Singh, along with additional solicitor general Aishwarya Bhati. The assessment showed a substantial decline in incidents of stubble burning across Delhi, Haryana, Uttar Pradesh and Rajasthan between October 21 and November 3. However, the same data also highlighted a "sharp increase in issues attributable to vehicular emissions", shifting the focus to what the bench described as an equally pressing source of pollution....