A rapidly growing mid-sized city faces severe traffic congestion, with traditional solutions (expanding roads, public transportation improvements) failing to keep pace with growth. The city has limited budget resources, political constraints, and engaged but polarized citizenry. Develop at least 5 innovative solutions that go beyond conventional approaches. For each solution, provide: (1) A clear description of how it would work, (2) Resource requirements and constraints, (3) Potential unintended consequences and mitigation strategies, (4) Implementation challenges and how to address them, and (5) Success metrics. Additionally, create a framework for testing and potentially combining elements from different solutions through a phased implementation approach that addresses political realities while maximizing impact.