Route Creation Method, Work Vehicle, And Autonomous Travel System

In a combine harvester, a terminal-side control device of a portable terminal functions as a route creation unit and a route determination unit. The route creation unit creates an autonomous travel route including a plurality of work routes for performing work in an unworked region of the field and a turning route connecting the two work routes. The route determination unit determines whether the position of the combine harvester during traveling of the combine harvester on the turning route and the position of the field outline satisfy a predetermined positional relationship with regard to the autonomous travel route, confirms the autonomous travel route when it is determined that the predetermined positional relationship is satisfied, and recreates the autonomous travel route to satisfy the predetermined positional relationship when it is determined that the predetermined positional relationship is not satisfied.