This paper examines the sustainability of railways. A comprehensive international literature review was conducted on railway vehicles, traction, and railway permanent way. The main goal was to find the factors and parameters that affect railway sustainability the most. CO2 emissions from transportation, mining, raw material production, manufacturing, use, operation and maintenance, and demolition and restoration must be significantly reduced. Naturally, the attention will be on the considerable energy and financial savings. This article's main topics are sustainability, affordable and clean energy, industry, innovation, infrastructure, sustainable cities and communities, responsible consumption and production, climate action, and life on land. Building materials come from quarries and gravel pits, but availability is decreasing. Future pavement construction and maintenance require recycling demolition and industrial waste. Engineers must choose materials and technology that extend track lifetimes to ensure reliability, availability, maintainability, safety, sustainability, and economy in permanent railroad ways. Life-cycle costs can be reduced, e.g., by Building Information Modeling. Electric machinery is preferred for construction equipment, materials, and management. Sustainability, like grassed tracks and recyclable plastics, has improved urban life. Sheet metal forming using recycled materials and sustainability shows how important environmental protection is in car and train design. Electric road and rail propulsion are driven by environmental concerns, while supercapacitors and batteries are studied. In conclusion, by preferring rail for freight and passenger transport, both for private and public transport, energy savings and CO2 emissions can be up to 2-10 times higher than for other modes of transport.