Autonomous Vehicles: A Critical Review (2004-2024) and a Vision for the Future

Henry Liu, Zhong Cao, Xintao Yan, Shuo Feng, Qiujing Lu

Autonomous vehicles (AVs) are among the most transformative technologies of the 21st century, reshaping our vision of transportation and mobility. Since the debut of the first prototypes in 2004, rapid technological breakthroughs have significantly advanced AV capabilities, culminating in real-world deployments such as robotaxi services. However, progress has recently slowed, and the path toward achieving safe, scalable, high-level autonomy remains uncertain. Meanwhile, a new wave of AI innovation, particularly in generative AI, is beginning to reshape the AV landscape. At this pivotal moment, critical reflection is necessary. This article highlights key achievements over the past two decades, focusing on major trends propelled by advances in AI. It traces the evolution from rule-based to data-driven approaches, reflecting a shift in design philosophy from "Autonomous Driving by Design" to "Autonomous Driving through Discriminative Learning." To frame this discussion, the article identifies safety and scalability as the two fundamental driving forces behind AV development, examining how successive paradigm shifts have sought to address them and envisioning future systems grounded in "Autonomous Driving through Generative Learning." This work presents a system-level perspective on key milestones, uncovers the forces driving progress and ongoing challenges, and offers visions and insights into future research directions.