Greenhouse gas emissions associated with road transport projects: Current status, benchmarking, and assessment tools

Global warming and climate change have been two much-debated topics in recent times due to their malevolent consequences not only to ecosystems, but also to the human race. They are indeed negative by-products of greenhouse gas (GHG) emissions. The transportation sector is a major contributor of GHG emissions, accounting for approximately 20 percent of all carbon dioxide (co₂) emissions globally, and road transportation accounts for the large majority of those emissions. This paper reviews literature related to GHG emissions produced by construction, operation, and maintenance phases of road projects. It compares country-specific GHG emission levels and provides input on assessment tools that can be used to estimate road project-specific GHG emissions. Lastly, the paper draws conclusions in regards to the magnitude of GHG emissions produced by road transportation, as well as to the status of assessment tools readily in the market. The authors find that GHG emissions continue to be a concern, especially in the Gulf Cooperation Countries (GCC), and recognize the need for reliable modeling tools capable of estimating project-specific GHG emissions. As a result, a model framework is proposed as the first step towards a comprehensive modeling tool capable of estimating GHG emissions produced during the entire life-cycle of a road project. The authors disclose that such tool is currently under development.