To rotate the operation of a car of an elevator as quick as possible by starting extra elevator cars enough to satisfy the demand of passengers from the upper or lower terminal floor on the basis of a measured value of passengers' demand at each floor and the estimated number of passengers in each elevator car.

This system includes a communication network 32 such as a local area network to which computers 24, 26, 28 are connected. Each elevator car has a motor as a power source for the car connected to a motor control device 36, and the motor control device 36 is connected to the communication network. For example, sensors 14, 16, 18, 20 related to estimation for passengers are directly connected to the car control computer 24 and the car control computer 28. The first car position-speed sensor 30-1 is directly connected to the car control computer 24 and the car control computer 28, and the second car position-speed sensor 30-2 is directly connected to the collision prevention computer 26.