This paper presents a new kind of train control system for branch lines which are operated by radio-based operational train control. Most branch lines with such operating limitations cannot afford the cost of investment for modern signalling systems. The train control system presented herein is a low cost solution which improves safety and introduces an interesting level of automation without any costly lineside installations. It is based on data radio communication between central computer and trains, cab signalling in the trains, and autonomous determination of train location using GPS and an odometer. In Austria this system has been in full operation for three years to gain practical experience, while the final approval is expected during summer 2006