The purpose of this chapter is to outline the operating principles of low emission zones (LEZs) in European countries and to evaluate their effectiveness. The impact of LEZs on urban sustainable development and climate change mitigation is assessed through a systematic review of the literature and practical applications. The chapter reviews a number of operational principles based on legal frameworks, technology-driven enforcement, and access control systems, which are essential for successful LEZ implementation. It also addresses the challenges faced and the costs of compliance for residents and businesses, emphasising the need for supportive urban policies and alternative transportation options. The study highlights significant achievements in pollutant reduction, with certain LEZ models demonstrating remarkable effectiveness in improving air quality. The key findings indicate that well-implemented LEZs can significantly reduce urban transport emissions, contributing positively to public health and environmental goals. The conclusion synthesises the primary contributions of the research, suggesting that effective LEZs are crucial for advancing health, equity, and urban policy. The chapter underscores the need to integrate LEZs with broader urban development strategies to ensure that future sustainability goals are met. The findings advocate policies that will enhance public acceptance and promote equitable outcomes.