BRTV provides "realtime" railway maps, showing where trains are on the UK railway network.
Data is supplied live from Network Rail, under licence, and shows where trains are on a signal by signal basis.
There are two levels of access: Standard Class and First Class.
Standard Class shows train positions with up to five minutes delay.
First Class shows where trains are within a few seconds, plus includes delay colour coding.
Each day we provide free access to one of our maps in First Class mode.
Today's free map is: Slough and Guildford Lines