Transport Infrastructure Ireland’s (TII) purpose is “to provide sustainable transport infrastructure and services, delivering a better quality of life, supporting economic growth and respecting the environment”. To this end TII is implementing a Sustainability Implementation Plan across its organisation. Transition to net zero emissions is a key pillar of this plan. As part of this transition, a carbon emissions assessment of the TII Pavement Renewals Programme was undertaken in Q1 2023. This is the first time TII incorporated a carbon emissions assessment in the identification of an optimal investment scenario, allowing them to better manage their long-term environmental impacts in line with European and national decarbonisation targets. Key activities relating to carbon emissions from road network pavement renewal, including the extraction, manufacture, transport, installation of materials and their reuse and recycling were assessed. The analysis quantified carbon emissions associated with four default treatments applied as part of the TII Pavement Renewals Programme; reconstruct, strengthen, overlay and replace surface. During the life of the pavement asset, users of the national road network generate varying carbon emissions depending on the condition of the road. Carbon emissions associated with a ‘Do Minimum’ scenario were compared with 7 different economic investment scenarios. Carbon emissions associated with a theoretical ‘Backlog’ were also calculated. These are the carbon emissions which would result from bringing the network back to “Good/ Very Good” condition at the end of the analysis period. A key finding is that the TII Pavement Renewals Programme can generate from 19 and up to 26 percent reduction in carbon emissions, a beneficial impact for an infrastructure investment. This paper sets out the findings of the assessment and the reasons why this investment, into a significant national transport asset, results in the identification of an optimum investment, in terms of carbon emissions, into the renewal programme for the Irish National Road network.