A sustainable transport system refers mainly to safety, green environment, and mobility, aiming at achieving zero road accidents, zero traffic emissions, and zero traffic congestion. The Sustainable Development Goals (SDGs) in Agenda 2030, adopted by the United Nations (UN), included a goal of halving the number of deaths from road accidents, listed in target 3.6. Another goal is to access safe, affordable, accessible, and sustainable transport systems for all, listed in target 11.2, in addition to a goal towards quality, reliable, green, smart sustainable infrastructure, listed in targets 9.1, 12.c, and 13.2. In line with the goals outlined in the SDGs Agenda 2030, this paper delves into the pivotal role of intelligent technologies such as the Internet of Things (IoT) and data analysis in shaping sustainable transport systems. It emphasizes the integration of these technologies to achieve the objectives of zero road accidents, traffic emissions, and congestion. Drawing from a comprehensive review of best practices across various countries, this paper critically assesses the key components contributing to the efficacy of Sustainable Urban Transport Systems. By synthesizing insights from extensive literature review and aligning with the SDGs, a set of key performance indicators (KPIs) is formulated to evaluate the functionality and success of sustainable transport systems within cities. These KPIs are delineated into three dimensions: Safe, Green, and Smart, providing a structured approach to quantitatively measure their performance and progress towards achieving the designated targets.