The world’s emerging economies are building out their road networks, to support trade through freight movement and improved personal mobility to access work, services, and goods. The world’s developed economies intend to keep the functionality of their road networks through maintenance and rehabilitation, regardless of future vehicle and propulsion types. Building and maintaining the world’s road infrastructure requires materials resources and energy, contributing to greenhouse gas emissions and global warming potential. The goal of this project is to produce a first-order estimate of future global warming potential from road building, maintenance, and rehabilitation for the world’s road networks and put this into context with other expected transportation-related greenhouse gases. This analysis is sorely needed as a component of future planning for low-GHG transportation systems. This project will be undertaken using information about existing networks, plans for future road networks, and estimates of their construction, maintenance and rehabilitation. The study will consider a full range of roadway types (local, arterial, highway), including pavement, earthwork, drainage, and bridges based on typical practice and occurrence. The research team will use life cycle assessment, involving tracking inventories for extraction, processing, and transport of materials, energy, and construction over typical life cycles and using the best available information regarding nationally or regionally typical roadway designs, and energy and fuel sources. The results will include sensitivity analyses to consider uncertainty in current data and future plans. The study will provide estimates of roadway infrastructure emissions that are important for planning strategies to reduce world GWP emissions.