This Seminar will address issues of track sustainability and provide participants with a general understanding of this increasingly important topic. The course takes a holistic view of the topic but highlights the issue of the infrastructure's CO2 footprint and measures to reduce it. The contents range from basic definitions to process topics (manufacturing routes), CO2 footprints of products (e.g., rail, sleeper) and systems (e.g., turnout) to Life Cycle Assessments.