This study presents a detailed age-wise mass-based emission factor (EFs), new fuel use estimate and develops spatially resolved emission inventories of fine aerosol constituents (PM2.5, BC, and OC) from the on-road transport sector in India. The national-level emissions of PM2.5, BC, and OC from the on-road transport sector in India are estimated to be 355 (104–607) Gg y‒1, 137 (47–227) Gg y‒1, and 106 (34–178) Gg y‒1, respectively, for the base year 2013. Our results suggest that the on-road transport sector in India contributes nearly 7%, 17%, and 6% of total PM2.5, BC, and OC emissions from India. The significant emissions of PM2.5 and BC revealed by super-emitter vehicles which comprise 24% of total traffic volume, but they contribute 67% and 47% to national level PM2.5 and BC emissions respectively. It indicates that eliminating the super-emitters could rapidly reduce emissions from the on-road transport sector in India. The emission estimates of carbonaceous aerosols are then used in CAM5 global climate model to estimate the direct radiative forcing (DRF) due to BC emissions from on-road transport in India. BC emissions from the road transportation sector in India results in a positive DRF up to 6 Wm-2 at TOA and negative DRF at the surface up to 10 Wm-2, thereby indicating trapping of energy within the atmosphere by up to 16 Wm-2 due to BC emissions from the on-road transport sector. With the rapid growth of economy and urbanization, the transport sector in India is likely to further expand in future and hence demands immediate attention for reducing BC burden and improving air quality over India.