Toll-computation device, control method, and program

This toll-computation device is provided with a toll-computation unit that computes a toll to be applied to a road-network area on the basis of the following: an aggregate traffic-flow rate (Q), which is the sum of the number of vehicles per unit distance per unit time as calculated for each target road within the road-network area; an aggregate QK relationship that indicates the correlation with an aggregate traffic density (K), which is the total number of vehicles within the road-network area; and an estimated aggregate traffic density (K) at a prescribed point in time.