The road sector is coming under pressure to review current practice and the potential to reduce carbon emissions. The life cycle approach has been accepted as a robust method of measuring carbon footprint. Tools and data-sets have been developed to facilitate the measurement. Among them is the Calculator for Harmonised Assessment and Normalisation of Greenhouse-gas Emissions for Roads (CHANGER) developed by International Road Federation (IRF) and aimed to measure and benchmark the carbon footprint of road construction worldwide.
This paper outlines the common methodology of road carbon footprinting, application of results in sustainable construction assessment schemes and resources available to undertake such analysis. Case studies of using CHANGER are provided for a UK trunk road widening, a public–private partnership highway construction in the United Arab Emirates and strategic highway upgrades in India. The CO2 output of these projects is compared, and an investigation is made to seek the causes of any differences.