(Refiles to correct spelling of hub in paragraph 1.) By Xihao Jiang and Casey Hall SHENZHEN, China, Nov 13 (Reuters) - A steady hum fills the air around busy tourist areas in China's southern tech. Civic and transport authorities are coordinating field operations to improve commuter safety, reduce transit bottlenecks, and streamline daily travel across key urban corridors. Commuters have been advised to check updated schedules and route advisories.