This chapter develops the concept of a “transportation immune system” within the framework of Urbanimmunology to address deep-seated problems in transportation. Drawing inspiration from mechanisms of the human immune system—such as barrier defense, adaptive response, immune memory, regulatory balance, coordinated combat, diversity generation, and regional specialization—it translates biological principles into systemic strategies for transport. This chapter outlines the architecture and functions of a transportation immune system, including multilevel protection, tolerance and resilience, precise regulation, diversified ecosystem safeguarding, autonomous operation, intelligent early warning, differentiated governance, and optimized resource allocation. A staged development path is proposed: digitalization and perception construction, intelligent algorithm development and collaboration, predictive regulation with optimization, and ultimately, autonomy with continuous evolution. By framing transportation as an adaptive, resilient organism, this chapter provides a novel paradigm for understanding, designing, and governing transportation systems capable of withstanding disruptions while fostering long-term sustainability.