Connected to its hydraulic power steering, the AgGPS Autopilot Steering Assistant automatically guides a tractor for straight rows. That can mean straight and permanent wheel tracks for subsequent field work, extended operation without conventional markers, reduced overlap to save time and input cost, and less driver fatigue and chance for error. The Steering Assistant system includes a navigational controller with safety monitor features, in-cab terminal, real-time Kinematic GPS receiver, remote display and logger, and light-bar for visual guidance.