<p>Transport sector is one of the very significant sources of air pollution. The environmental effects of transport are huge because transport sectors are the major user of energy, and it burns most of the world's petroleum. Within the transport sector, road transport is the largest contributor to air pollution. Carbon emission from conventional fuels such as petrol and diesel contribute significantly to this pollution. Sustainable approach to urban transport addresses the environmental concerns with the need to provide affordable mobility choices to the rapidly growing population of urban areas. The aims to validate compressed natural gas (CNG) as a safe alternative vehicular fuel to reduced CO₂ emission in Agartala city. For that reason an attempt for conversion of vehicles running on harmful conventional fuels into CNG fuel in AMC area under three intervention scenarios has been undertaken and analyzed. The present study also makes use of IDW interpolation method to mark out areas under different CO₂ levels. The result reveals a huge change in environmental status which makes it appropriate to conclude that use CNG as a vehicular fuel is the best sustainable approach in urban surface transport to significantly reduce CO₂ emission.</p>