Temporal assessment of emission inventory model for Indian heavy commercial vehicle segment: A top-down approach

Abstract

Heavy commercial vehicles (HCVs) are pivotal to India's economy, but are also significant sources of air pollution. To address this issue, the Indian government implemented Bharat stage VI (BS-VI) emission standards in 2020. Research gap regarding realistic inputs for annual vehicle kilometres and survival rate of HCVs has been identified. The HCV sector is categorized into long-haul vehicles (32 t and above, with higher annual vehicle usage and survival rates) and pick-up and delivery HCV trucks (16–32 t, with relatively lower annual vehicle usage and survival rates). Based on the primary research by taking into account the inputs from various stakeholders regarding annual vehicle kilometres and survival rates subject to vehicle type and emission standards, an HCV emission inventory for India has been developed for regulated pollutants (NO_x, PM_2.5, and CO) till 2035. We assume no additional external technological or policy interventions, except the anticipated shift to Bharat stage VII (BS-VII) standards by 2027. Key findings reveal that the on-road HCV population is projected to marginally increase (6.5%) by 2035 compared to 2020. However, there is a notable 97% surge in goods transport tonnage by 2035, indicating more efficient commercial vehicle usage, especially in the heavier category (32 t and above). Crucially, annual emissions of NO_x, PM_2.5, and CO from the HCV segment are expected to peak in 2020, and decline significantly by 2035. Emissions are projected to decrease by 91.5% (NO_x), 96.6% (PM_2.5), and 97.6% (CO) compared to 2020 levels due to the introduction of BS-VI standards in 2020 and the anticipated adoption of BS-VII standards in 2027. This study is instrumental in defining base emission inventory till 2035 for any further policy evaluation for the HCV segment for reducing air pollution and enhancing environmental sustainability.