Vehicular Emissions Control in India: Challenges and Legal Framework

Introduction-

India’s motorisation over the last three decades has been astounding: from a few tens of millions in the 1990s to well over 300 million now, car registrations have increased dramatically, changing both air quality and transportation in all of the country’s main cities. In cities today, vehicle emissions are the main source of nitrogen oxides (NOx), particulate matter (PM₂.₅ and PM₁₀), carbon monoxide (CO), and volatile organic compounds (VOCs). If policy is successful, reducing CO₂ and black carbon will also have a positive impact on the climate. Controlling these emissions is a complex issue that involves several interconnected elements: India’s multi-statute environmental framework and constitutional federalism, as well as fuel and vehicle standards, in-use compliance, inspection and maintenance, scrappage, modal shifts, and emergency response measures during acute smog episodes. The main enforcement methods and institutions are identified, the fundamental legislative framework controlling vehicle emissions in India is mapped, and recent changes, especially in the National Capital Region (NCR), that indicate the direction of travel are assessed.

The Statutory Architecture-

General environmental statutes, sector-specific transportation laws, and delegated regulations form the foundation of India’s air quality administration.
Prevention and Control of Air Pollution Act, 1981. The Air Act allows for the establishment and enforcement of standards, requires the prevention and control of air pollution, and creates the Central and State Pollution Control Boards. Although transportation legislation is mostly responsible for administering vehicle emissions, the Air Act offers the overall institutional framework (e.g., performance monitoring, advisories, coordination).¹ (India Code)

In order to establish ambient standards, define pollutant limitations, and oversee the closure or control of polluting operations, Environment Protection Act (EPA), 1986 grants the Union executive extensive rule-making and order-issuing authority. National Ambient Air Quality Standards (NAAQS, 2009) are hosted by its regulations (most notably the Environment (Protection) Rules), which also enable cross-sectoral initiatives that frequently touch on transport policy. (India Code, Central Pollution Control Board)

The Central Motor Vehicles Rules (CMVR),1989 and the Motor Vehicles Act (MV Act), 1988. These are the foundations of transport legislation. The MV Act gives the Union the authority to establish standards for construction, machinery, and upkeep; it also gives states the authority to enforce these requirements and to penalise noncompliance, including emissions infractions. The primary delegated regulation that specifies in-use testing and PUC requirements as well as vehicle-level emission restrictions (Bharat Stage norms) is CMVR regulation 115. ³

The National Capital Region and Adjacent Areas Commission for Air Quality Management Act, 2021 (CAQM Act). The CAQM Act, a region-specific law for the NCR, establishes a supra-regional body with the authority to make legally enforceable directives for air-quality control that cut across sectoral silos (transport, fuels, construction, and industry). Delhi and the surrounding regions of Haryana, Punjab, Rajasthan, and Uttar Pradesh are specifically covered.⁴ (India Code)

These laws work together: the CAQM Act concentrates jurisdiction and emergency powers in the NCR; the MV Act/CMVR regulates vehicle and fuel compliance and in-use regulations; the EPA provides ambient standards and a strong backstop; and the Air Act provides institutions and coordination.

Emission Standards: From Bharat Stage I to BS VI and Beyond-

India’s tailpipe emission regulations follow the EU’s “Euro” route through the “Bharat Stage” (BS) regime, which is governed by CMVR Rule 115. The national plan resulted in a leapfrogging decision to synchronise vehicle technology (e.g., advanced aftertreatment like DPFs and SCR) and fuel sulphur level (10 ppm) by going straight from BS IV to BS VI countrywide on April 1, 2020. ⁵ CMVR Rule 115, which specifies restrictions per fuel and category through a complex web of Gazette notices, provides the legal hook. ⁶

On-Board Diagnostics (OBD II) upgrades and Real Driving Emissions (RDE) conformance factors were introduced with BS VI Phase 2, which went into effect on April 1, 2023. This was a significant tightening that brought compliance closer to real-world settings rather than just laboratory cycles. Technical specifics are established by MoRTH notifications under CMVR, but their significance is simple: cars must adhere to specified tolerances when driving as well as meeting restrictions on the test bench. ⁷

Fuel quality is also important: for BS VI diesel vehicles’ DPF/SCR systems to operate, low-sulfur fuels (10 ppm S) are required. In order to ensure that vehicle and fuel readiness are in sync, the supply is coordinated through petroleum standards and announced timetables for a countrywide rollout. These fuel stages are combined with the CMVR emissions calendar. (CMVR provides more clarity on the legal origin of vehicle standards; fuel specifications are notified separately but are harmonised in reality.) ⁶

In-Use Compliance: The PUC System and Its Upgrade-

For the current fleet, the main in-use compliance tool is the Pollution Under Control (PUC) regime. Every vehicle must have a valid PUC certificate with a six-month validity (increased to twelve months for BS IV/BS VI vehicles) within a year of first registration, according to Rule 115(7) CMVR. On demand, the certificate must be supplied; if non-compliance continues, sanctions and possibly registration suspension may result. (Press Information Bureau, Motor Vehicle Department Kerala)

In June 2021, MoRTH pushed for integration with the VAHAN database (first notified in 2018) to centrally gather test results, standardised the PUC form nationwide (QR-coded, data fields harmonised), and required electronic data submission in an effort to modernise PUC and combat fraud. Additionally, the notification highlighted the penalties of enforcement and added “rejection slips,” which are documentation of failed tests. (Press Information Bureau, India Today, The Times of India)

Uneven implementation persists. Gaps in state-level integration of PUC modules with VAHAN and uneven supervision of PUC centres (calibration, random inspections) are frequently highlighted in Comptroller and Auditor General observations and MoRTH warnings, undermining the system’s deterrent effect. ¹⁰ ¹¹(Comptroller and Auditor General of India, morth.gov.in)

Complementary Levers: Efficiency and Fleet Renewal-

CAFC/CAFE stands for Corporate Average Fuel Consumption/Efficiency. India has enacted corporate average fuel consumption rules for passenger automobiles in addition to tailpipe pollution regulations, which lower fuel consumption and CO₂ and so reduce criterion pollutants. Through CMVR modifications and BEE supervision, these standards—which are phased in and regularly tightened—are applied to manufacturer fleet averages. (The MV Act’s transport rule-making system includes the full GSR notices.) ⁶

Registered Vehicle Scrapping Facilities (RVSF) and Regulations and Vehicle Scrappage Policy, 2021. In order to operationalise a network of approved dismantling facilities, fitness testing, and incentives for the voluntary retirement of outdated cars, the Union notified G.S.R. 653(E) in September 2021. End-of-life vehicles (ELVs) with disproportionately high emissions are the focus of scrappage, which aligns with NCR age-based limitations (see below). (Press Information Bureau)

FAME II: Electric Mobility Incentives. In order to transition the fleet to zero tailpipe emissions in urban corridors, FAME II (2019) offers demand incentives for electric two-wheelers, three-wheelers, buses, and restricted four-wheelers. Through the displacement of ICE km, the strategy directly improves urban air quality, while being essentially a climate/industrial policy tool.¹³(India Code)

NCR’s Special Regime: CAQM, Age Bans, and Denial of Fuel-

Special judicial and legislative actions were brought about by the extreme AQI incidents and ongoing winter pollution in the National Capital Region.

Orders on Old Vehicles from the Supreme Court and NGT. The National Green Tribunal outlawed petrol cars older than 15 and diesel vehicles older than 10 in Delhi in Vardhaman Kaushik v. Union of India (2014–2015). The Supreme Court later supported and upheld this decision in M.C. Mehta v. Union of India (ruling dated 29 October 2018). In the NCR, these orders have provided the legal basis for denying registration and impounding older cars. ¹⁴(Press Information Bureau)

Restrictions on Diesel Registration (2015–2016). The Supreme Court temporarily prohibited the registration of more than 2000 cc diesel vehicles in Delhi-NCR in December 2015 due to a severe pollution outbreak; however, the prohibition was eventually lifted with a 1% environment cess. Despite being transitional, the episode shows how courts are prepared to apply sector-specific restrictions when environmental circumstances worsen. ¹⁵(Press Information Bureau, The Indian Express)

Binding Directions and the CAQM Act (2021). The CAQM currently runs the Graded Response Action Plan (GRAP), gives binding Directions under Section 12, and organises responses across the NCR. Recent directives seek to operationalise the NGT/SC restrictions on the ground by denying fuel to ELVs (i.e., petrol >15 years; diesel >10 years) at retail outlets through the use of ANPR and database checks. Although the core legal foundation has not changed, rollout timeframes have been modified to accommodate interoperability and enforcement logistics. ¹⁶ ¹⁷ ¹⁸(India Code, caqm.nic.in, The Times of India)

Recent Changes in Litigation (2025). As it re-examines several parts of the 2018 blanket ban, the Supreme Court ruled in August 2025 that owners of 10-year diesel and 15-year petrol cars in Delhi-NCR will not be subject to coercive action. The dynamic, litigation-driven nature of NCR policy is highlighted by the interim ruling, which temporarily modifies enforcement awaiting a further hearing but does not eliminate the NGT/SC age limitations. ¹⁹(The New Indian Express)

Enforcement Mechanics and Penalties-

The punitive chapter of the MV Act deals with emissions non-compliance, which includes operating a vehicle without a valid PUC and interfering with pollution control equipment. Violations of this section can result in penalties and even impoundment. According to the 2021 PUC changes, the registering authority may suspend the certificate of registration and permits until a valid PUC is generated if the vehicle is not presented for compliance within seven days. This escalation is intended to increase the incentives for compliance.²⁰ (Motor Vehicle Department Kerala)

In the NCR, the CAQM Act gives the Commission the authority to give legally binding directives to both government agencies and private entities, along with environmental compensation mechanisms and the ability to prosecute violators under the Act or the EPA. It also grants the Commission the authority to supersede other laws in the event of inconsistency. Since permeable jurisdictional borders would otherwise jeopardise localised interventions, these technologies are essential for cross-border alignment between NCR states.²¹(India Code)

Ambient Standards, Planning, and the National Clean Air Programme (NCAP)-

Policy goals are guided by ambient norms, whereas sources are governed by vehicle standards. India’s NAAQS (2009), which serve as the foundation for compliance methods, set limitations for PM, NO₂, SO₂, ozone, CO, and other pollutants. With the help of federal financing and city-level action plans that frequently give priority to transport initiatives including cleaner buses, EVs, modal shift, traffic management, and PUC enforcement blitzes, the National Clean Air Programme, 2019 offered a planning blueprint for more than 100 non-attainment cities. (NCAP depends on state/ULB execution and is a part of EPA/NAAQS.) ²²²³(SCCL Mines)

Persistent Challenges-

(1) Type Approval vs In-Use Emissions. Even with BS VI technology, tampering (e.g., removal of DPF), poor repairs, and maintenance failures can cause real-world emissions to exceed lab limits. While RDE conformance factors are helpful, regular inspections and strong anti-tampering measures are necessary for long-term compliance. The PUC test matrix (opacity/CO/HC) is still restricted and cannot confirm the health of patients today after therapy.

(2) Disjointed Capacity for Implementation. States differ greatly in terms of PUC centre calibration, operator training, and anti-fraud supervision. The compliance signal is diluted by audit results that indicate inconsistent uploads to VAHAN, underutilisation of digital modules, and poor enforcement follow-through. ¹⁰ (Comptroller and Auditor General of India)

(3) Equity and Legacy Fleet. The NCR’s age-based prohibitions quickly eliminate high-emitting cars, but they also create distributional issues because low-income users frequently buy older cars. For changes to go well, scrappage incentives, concessional financing, or retrofits are necessary. High-mileage sectors will be shifted first, according to the CAQM’s latest guidelines for transitioning greener buses and aggregator fleets. ¹⁶(caqm.nic.in)

(4) Quality of Fuel and Maintenance. Consistent fuel sulphur and urea (AdBlue) quality is essential for BS VI. Field reports regularly indicate poor-quality reagents or supply-chain breaches, resulting in malfunction indication lamps and derating; standards enforcement along the fuel and reagents chain is as critical as vehicle compliance.

(5) Transboundary Externalities Across Multiple Cities. Sources of Delhi’s air pollution include upwind industrial clusters and stubble burning in Punjab and Haryana. Although the regional mandate of the CAQM is helpful, most Indian cities do not have a similar supra-state framework. Ambient compliance involves regional airshed administration, not merely city action.

Emerging Directions-

Inspection and Maintenance (I/M) has been modernised. India is coordinating PUC data, e-challans, and registration databases while implementing enhanced I/M regimes, such as OBD inspections, on-road remote sensing (RSD), and periodic fitness for older/private cars. The VAHAN connection and the QR-coded standardised PUCC are first steps towards a data-driven approach that more precisely targets gross emitters. ⁹ ¹¹ (Press Information Bureau, morth.gov.in)

ELV Data-Led Denial-of-Fuel. Age limits are operationalised with fewer roadside contacts thanks to NCR’s decision to use ANPR-enabled fuel denial, as long as mistake rates are kept low and grievances are promptly resolved. The infrastructure complexity is reflected in the phased deadlines (Delhi first, followed by other NCR districts), which, once stabilised, promise tougher, less leaky enforcement.¹⁷ ¹⁸(The Times of India)

cleaner fleets of aggregators and the general public. According to CAQM’s 2025 guidelines, buses and aggregator/delivery fleets should quickly switch to cleaner modes. These are categories with large usage and significant air-quality advantages per vehicle. The on-road stock of zero-emission kilometres increases significantly as aggregators embrace electrified two- and three-wheelers and states acquire e-buses under various initiatives. ¹⁶(caqm.nic.in)

Stricter Manufacturer Requirements. Manufacturer in-service conformance and recall procedures will probably become more stringent as RDE monitoring develops. India’s regulatory framework increasingly reflects EU standards by fusing data openness, in-use inspections, and advanced type certification.

incorporating climate policy. There are immediate benefits to local air quality from transport decarbonisation (e.g., fuel economy standards, EV uptake, and modal shift to rail/metro). Anticipate more clear co-design between FAME, CAFC/CAFE, and air-quality planning, particularly as cities strive for PM₂.₅ reductions under NCAP extensions.

Conclusion-

From simple tailpipe inspections to a complex, multi-statute system that covers design (BS VI/RDE), usage (PUC/I&M), end-of-life (scrappage/age limitations), and emergency measures (GRAP, denial of fuel), India’s vehicle emissions control regime has changed throughout time. When the stakes—human health and the constitutional rights to life and clean air—are high, the NCR’s CAQM Act provides a potent supra-regional layer that may coordinate activities across state boundaries.

Two gaps, however, are still crucial. The first is durability of compliance, which bridges the gap between type certification and in-use performance by using a strong, data-connected, fraud-resistant inspection system that really identifies and discourages high emitters. Second, institutional coherence: maintaining the capacity to take immediate action during smog emergencies while coordinating Union notifications, state enforcement, and court directives within a stable, predictable system that families and companies can plan around.

Real progress has been made: twenty years ago, it would have been impossible to imagine BS VI/RDE cars, standardised digital PUC, scrappage regulations, and NCR’s data-driven fuel denial program. Scaling rigorous I/M across the country and speeding up fleet electrification of high-mileage sectors are the next big steps that will secure the critically needed health improvements in Indian cities.

Notes and References (OSCOLA style)-

1. Air (Prevention and Control of Pollution) Act, 1981, No 14 of 1981, India Code. (India Code)
2. Environment (Protection) Act, 1986, No 26 of 1986; Environment (Protection) Rules, 1986; National Ambient Air Quality Standards (2009). (India Code, Central Pollution Control Board)
3. Motor Vehicles Act, 1988, and Central Motor Vehicles Rules, 1989, esp Rule 115 (emission). Consolidated access and explanatory materials (Rule 115/116 extracts and enforcement notes).
4. Commission for Air Quality Management in National Capital Region and Adjoining Areas Act, 2021, No 29 of 2021. (India Code)
5. On the BS roadmap culminating in BS VI nationwide from 1 April 2020 (vehicle/fuel alignment), see CMVR Rule 115 notifications and official handbooks summarizing the standards lineage.
6. CMVR Rule 115 framework for pollutant limits and compliance, including BS VI specifications and sub-rule obligations.
7. BS VI Phase 2 (RDE/OBD II) effective 1 April 2023 under CMVR notifications; see consolidated CMVR references.
8. PUC requirement and validity: Rule 115(7) CMVR; Government of India (PIB) press note summarizing standards and validity for BS IV/BS VI vehicles. (Press Information Bureau)
9. G.S.R. 410(E) (14 June 2021): standardized PUCC format; linkage and QR features; contemporaneous coverage. (Motor Vehicle Department Kerala, India Today, The Times of India)
10. CAG/Compliance: Illustrative audits highlighting underutilization of PUC-VAHAN modules. (Comptroller and Auditor General of India)
11. MoRTH advisory on PUC–VAHAN electronic uploading (2018) and subsequent updates. (morth.gov.in)
12. Motor Vehicles (Registration and Functions of Vehicle Scrapping Facility) Rules, 2021, G.S.R. 653(E) (23 Sep 2021). (Press Information Bureau)
13. FAME India Phase II (2019) scheme documentation and guidelines (Department of Heavy Industry). (India Code)
14. Vardhaman Kaushik v Union of India, NGT O.A. No. 21/2014 (orders of 26 Nov 2014 and 7 Apr 2015) and M.C. Mehta v Union of India (Supreme Court order 29 Oct 2018) upholding NCR age bans; official PIB statement summarizing orders. (Press Information Bureau)
15. M.C. Mehta orders on >2000 cc diesel registration in Delhi-NCR (Dec 2015 ban; Aug 2016 lifting with 1% cess); reported summaries. (Press Information Bureau, The Indian Express)
16. CAQM Directions (e.g., Directions 2025 on fleet migration; CAQM site—Acts & Rules and scrolling marquee of directions/orders). (caqm.nic.in)
17. Denial of fuel to ELVs roll-out and SOPs; recent enforcement updates for Delhi and NCR districts. (The Times of India)
18. Revised enforcement dates and ANPR-enabled implementation across NCR; news summaries of CAQM orders. (The Times of India)
19. Supreme Court (Aug 12, 2025): interim order directing no coercive action against owners of 10-year diesel/15-year petrol vehicles pending re-examination of the 2018 blanket ban. (The New Indian Express)
20. G.S.R. 410(E) (2021) also clarifies enforcement escalations: failure to present within seven days can trigger suspension of registration until a valid PUCC is generated. (Motor Vehicle Department Kerala)
21. CAQM Act, 2021: powers, overriding effect, and rule-making notifications (IndiaCode repository). (India Code)
22. Environment (Protection) Rules, 1986 (hosting ambient standards/NAAQS) and CPCB guidance pages. (Central Pollution Control Board)
23. NCAP (2019) overview and non-attainment city planning framework under MoEFCC/CPCB. (SCCL Mines)