Perform a comprehensive threat model assessment for a hypothetical 'Smart City Traffic Management System.' The system consists of: 1) IoT sensors at intersections (cameras, magnetic loops), 2) Edge computing nodes for local processing, 3) A central cloud command center, and 4) A public API for third-party navigation apps. Use the STRIDE methodology (Spoofing, Tampering, Repudiation, Information Disclosure, Denial of Service, Elevation of Privilege) to identify potential attack vectors. For each identified threat, propose a specific mitigation strategy involving cryptography, network segmentation, or physical security controls. Prioritize the threats by impact and likelihood.