This paper presents a methodology for assessing the sustainability of pavements through indicators. There are increasingly different procedures, technologies and practices to increase the sustainability of construction works. Especially in the field of roads, research work is being carried out to develop new asphalt mixes with low emissions, as well as to promote the reuse of recycled materials. All of these practices will greatly contribute to sustainability. However, sustainability is a relative parameter that should be used for comparison. There are no sustainable activities in absolute terms, but there are activities that are more or less sustainable compared to others. When the sustainability of two different products or activities is evaluated, the aim is to compare them and, therefore, the evaluation must be carried out following a homogeneous procedure. This paper introduces a methodology based on KPIs that will provide pavement designers with a tool to quantify and compare the sustainability of different pavement structures in order to select the best pavement alternative from a technical, economic and sustainable point of view.