This thesis presents an investigation into a novel method of estimating the trajectory (future direction and elevation) of a vehicle, and subsequently influencing the control of an engine. The technique represents a convenient and robust method of achieving road prediction, to form a fuzzy system that „looks ahead‟, leading potentially to improved fuel consumption and a consequent reduction in exhaust emissions. The work described in this thesis brings together two modern technologies, Neuro-fuzzy techniques and Global Positioning System, and applies them to engine/vehicle control.