Analyzing the impact of the built environment on commuting-related carbon dioxide emissions

Abstract

It is critical to understand the elements that influence CO2 emissions from commuting to establish low-carbon transportation and land-use regulations. Research attempted to determine the mechanisms by which the built environment (BE) influences commuting-related CO2 emissions. Most research was conducted in developed nations and used traditional modeling to evaluate the relationship between BE and CO2 emissions primarily considering direct consequences related with BE. There is a research vacuum in predicting the total impacts of BE on CO2 emissions from commuting, taking into account the mediating effect of car ownership. This research examines total effects of the built environment (BE) on commuting-related CO2 emissions including both direct and indirect effects. We used 10,592 home-based work trips from Dhaka, a developing city, to create a structural equation model (SEM) for predicting this association. We included car ownership as a mediating variable and treated BE, car ownership, and CO2 emissions as endogenous variables. Both population density and land-use diversity are positively associated with private car ownership. The study shows the built environment plays a different role in explaining CO2 emissions from commuting in developed and developing countries. Population density has a direct positive impact on CO2 emissions, as evidenced by previous research in a developing metropolis. Because of its mediating effect on car ownership, land use diversity has a considerable positive indirect impact on emissions but a negligible overall effect, making it ineffective on its own and necessitating the implementation of complementing Travel Demand Management (TDM) policies. Our modeling results are comparable with those from both developing and developed countries in terms of public transportation accessibility, job accessibility, and road network design. The results might be used to produce policy guidelines to reduce car ownership and CO2 emissions, which would help developing countries in South Asia meet their sustainable development goals.