Links to the use of modern day signalling in the UK: -
http://en.wikipedia.org/wiki/British_railway_signals
http://www.davros.org/rail/signalling/articles/junctions.html
http://www.railway-technical.com/sigtxt1.html#MultiAspectSignals
http://www.railway-technical.com/sig-uktypes.html
Dave
http://en.wikipedia.org/wiki/British_railway_signals
http://www.davros.org/rail/signalling/articles/junctions.html
http://www.railway-technical.com/sigtxt1.html#MultiAspectSignals
http://www.railway-technical.com/sig-uktypes.html
Dave