The ever-increasing global demand for hydrocarbon has brought new challenges in drilling through offshore and shale reservoirs. Bringing automation to directional drilling aims to address these challenges by reducing non-productive time (NPT) while drilling more accurate and smoother boreholes. This paper discusses the architecture, testing and field validation of a steering advisory system deployed for mud motors, which automates the steering-related decisions. The predictive performance of the advisory system is tested on 20 commercial jobs across North America for different motor sizes, stabilizer configurations, and hole diameters. The resulting performance, measured in terms of positional accuracy and precision, indicates a reliable prediction relative to the surveys. Furthermore, several curve sections were drilled entirely by following the steering decisions provided by the advisory system, resulting in successful landing within tight targets.