This document is a literature review on the decarbonisation of the road transport sector, prepared by PIARC Technical Committee 3.5 (Road Infrastructure for Road Transport Decarbonisation). It supports the PIARC Strategic Plan 2024–2027 and aims to guide governments, road authorities, and stakeholders in designing and implementing strategies, policies, and solutions to meet greenhouse gas (GHG) reduction targets in line with the Paris Agreement. The transport sector must reduce its emissions by 70–80% from 2015 levels by 2050, making it the fastest-decarbonising sector. The report develops a conceptual map (taxonomy) that organises the complex challenges of road transport decarbonisation into ten key areas. Each area is supported by selected references, examples, and lessons learned. 
The review underscores that road transport accounts for 70–90% of transport-related emissions, and unlike other sectors, its emissions continue to rise. Decarbonisation requires coordinated action to shift from business-as-usual to sustainable models, combining demand management, modal shift, technology innovation, circular economy practices, and robust financing. Comparative case studies reveal diverse national approaches: some countries (e.g. Norway, the Netherlands) set ambitious bans on internal combustion vehicles, while others (e.g. Canada, France, Japan) combine neutrality targets with subsidies, infrastructure expansion, and hydrogen strategies. Despite varied pathways, all converge on achieving climate neutrality by 2050 or 2060 (the latter mostly for emerging and developing Countries). The report also dedicates a chapter to Low- and Middle-Income Countries (LMICs), highlighting both challenges (resource constraints, regulatory gaps, infrastructure needs) and opportunities (technology leapfrogging, international financing, integration with urban planning). 
Future steps include expanding the literature base, analysing the effectiveness of national strategies, and documenting lessons learned from road authorities to accelerate adoption of best practices.