Movable speed reducing mechanism

The invention discloses a movable speed reducing mechanism which comprises a speed reducing device arranged based on roadbeds on the two sides, the two sides of the speed reducing device are each fixedly connected with an electric trolley through a spring, and the electric trolleys are installed in guide rail sets arranged on the roadbeds. The guide rail set comprises a first guide rail and a second guide rail which are arranged on the same roadbed, the first guide rail is arranged on the side close to the road surface, a sliding groove is formed in the upper end face of the first guide rail,a discharging channel is formed in the first guide rail, and one end of the first guide rail is connected with a water discharging pipe and connected into a sewer through the water discharging pipe. The whole speed reducer can be automatically moved according to the road ponding condition, a temporary speed reducer is built on a ponding road section, the speed of a vehicle passing through the areais reduced, and meanwhile