Act as a visionary urban designer with 20 years of experience in biomechanical architecture. Design a futuristic city where the streets are sentient, pulsing with life and adapting to the needs of its inhabitants. Describe the [MATERIALS] used to construct these living pathways, the [BIOLOGICAL SYSTEMS] that allow them to grow and repair themselves, and the [SYMBIOTIC RELATIONSHIP] between the city and its residents. Include details on how the streets communicate, their daily rhythms, and how they respond to emergencies like overcrowding or natural disasters. Your design should be both awe-inspiring and functional, blending organic and technological elements seamlessly.