The Department for Transport (DfT) has published guidance introducing a local transport infrastructure carbon benchmarking tool intended to help local authorities estimate carbon emissions from transport projects. The spreadsheet-based tool applies a top-down benchmarking approach using predefined standards and case studies to estimate infrastructure carbon impacts for interventions such as cycle lanes, roads, bridges and charging infrastructure, particularly where detailed design information is unavailable at early stages of scheme development. Users input details including intervention type, carbon intensity, quantity and construction timeframe, enabling the tool to generate estimates of emissions primarily for product and construction stages, alongside limited projections of maintenance, repair and replacement impacts over time, with outputs summarised by intervention, category, lifecycle stage and cumulatively. The tool is designed to inform early-stage planning and appraisal, including local transport plans and business cases, but is not a substitute for detailed bottom-up carbon assessments at later stages and does not provide a full whole-life carbon assessment, as it excludes user-related emissions.