Evaluate the effectiveness of fleet-transition mandates (BS-VI/CNG/EV) and vehicle-scrapping incentives in reducing urban vehicular emissions.

Fleet-transition mandates allow only cleaner vehicles (BS-VI, CNG, LNG or EV) to enter a city or join a fleet. Scrapping incentives pay owners to retire old vehicles. Delhi-NCR now uses both at once, which makes it a good test of whether they work.

Effectiveness: Where the Tools Work

• Targets heavy emitters at the border: CAQM Direction No. 88 lets only BS-VI/CNG/LNG/EV goods vehicles enter Delhi from 1 November 2025 [3]. Direction No. 93 applies the same rule to buses from 1 November 2026 [4].
• Legal force: these are statutory directions issued under the CAQM Act, 2021, not advisories [3].
• Incentives alongside bans: the ₹9,585-crore NCRPB scheme pays for replacing BS-IV-and-older trucks and buses. In Delhi, replacement LGVs must be electric and buses BS-VI CNG/EV [1].
• Lower transition cost: interest subvention, fuel vouchers, State tax waivers and OEM discounts reduce the cost for transporters [2].
• Next steps planned: CAQM's Expert Committee is drawing up regulatory, technological and incentive-based measures for transport [6].

Limitations: Where They Fall Short

• Narrow coverage: both directions exempt vehicles registered in Delhi [3][4]. Private cars and two-wheelers fall outside the directions and the scheme [1].
• Moves emissions instead of cutting them: eligible BS-IV vehicles may be sold to non-NCAP cities outside the NCR [2]. Their pollution simply shifts elsewhere.
• Weak enforcement base: the CAG found that over 1.08 lakh vehicles got PUC certificates despite excess CO/HC emissions. Delhi also had no data on the vehicles running on its roads [5].
• Slow retirement of old vehicles: only 2.98 lakh of 47.51 lakh end-of-life vehicles were deregistered in Delhi between 2018-19 and 2020-21 [5].

Verdict and Way Forward These tools are moderately effective. They work well for commercial fleets but do little for private vehicles, and enforcement is weak. The next steps should be to:

• phase in the norms for Delhi-registered and private vehicles;
• audit PUC centres and add roadside remote sensing;
• require scrapping of old vehicles instead of allowing resale;
• pair the mandates with affordable public transport.

Fleet mandates and scrapping incentives have started to clean up heavy vehicles. A lasting cut in urban vehicular emissions needs an approach that covers the whole fleet, relies on good data and is backed by credible enforcement. A gradual transition in line with SDG 11.6 on urban air quality can protect the Article 21 right to clean air while sparing livelihoods.