Travelling by train is one of the safest methods of transport and fundamental to this is the signalling system. But will new technology mean the end of the line for the signalmen or are there economic and social factors that could secure the role of the signalbox as part of the railway system for another 150 years? in a new series, BBC transport correspondent Alan Whitehouse visits five signal boxes to find out howthey work and meets signalmen and women, past and present.
1: Bewdley North. The first leg of his journey is on a preserved steam line, the Severn Valley Railway. Producer Andy Cartwright