A measurement method includes: a physical quantity acquisition step of acquiring, based on observation information obtained by at least one observation device that observes first to N-th observation points of a structure arranged along a second direction intersecting a first direction in which a moving object moves along the structure, physical quantities at the first to N-th observation points; and an action calculation step of calculating actions x1 to xN on the first to N-th observation points based on the acquired physical quantities at the first to N-th observation points, on the assumption that, when a function indicating a correlation between an action xj on a j-th observation point and an action that the action xj has on an i-th observation point is set as yij, an acquired physical quantity at the i-th observation point is equal to a sum of values of functions yi1 to yiN.