SURVEYING ASSISTANCE DEVICE, SURVEYING ASSISTANCE SYSTEM, SURVEYING ASSISTANCE METHOD, AND STORAGE MEDIUM

A surveying assistance device is a computer configured to read design information including center point data of a center point set on a centerline of a route and constituent point data of constituent points set on a section including the center point, the section being orthogonal to the centerline, acquire position information indicating a current position of a surveyed device with a predetermined period, creates a plan view from the design information and display the plan view on a terminal screen unit, display the current position on the plan view and updates the display every time the position information is acquired, record the acquired position information in a storage as an observation data, and display reference lines indicating positions which are distant from the designated section backward and forward in a route direction by a preset distance limit on the plan view.