The London Underground train lights you may have noticed and what they mean

ATO light on an S Stock train
The white light illuminated on the side of this train means it will depart within a matter of stories -Credit:Callum Marius

Ever wondered what those lights on the London Underground trains mean? Well, MyLondon is here to help you out. When you're stuck on a platform waiting for your train to depart, it can be quite disorientating.

Communication is key, but during service disruption, it's not always forthcoming. But don't worry, we've got a handy tip that will help you feel less anxious the next time you encounter a delay.

READ MORE: Underground's rare sections where you'll end up waiting at least 30 minutes for a train

On the Tube lines equipped with automatic train operation (ATO), there are lights located on either or both the trains or platforms which indicate whether the train is about to depart. On the lines which use 'S Stock' or '2009 stock' Tube trains - the Circle, District, Hammersmith and City, Metropolitan and Victoria - when trains are about to depart (usually within 15 seconds) a white light will illuminate above the windows on the carriage exterior.

If you see a white light and you're hoping to hop on one of these trains, we recommend not taking the risk as departure is imminent and getting trapped in the doors can lead to serious injury!

Hopefully, you're already on the train, spot the white light in the window reflection and will be well on the way in a matter of seconds.

On the Central, Jubilee and Northern lines, these lights are located at the end of the platforms, nearest to the front of the train in the direction of travel. When the light on the platform changes from red to white or lights up white, it's a signal that the train is ready to depart.

In both cases, the light remains a steady white and shouldn't be mistaken for other flashing white lights elsewhere on the train or platform as they could signify different things. The Bakerloo, Piccadilly and Waterloo and City lines, along with some sections of other lines that don't use automatic train operation, still utilise traditional 'traffic light'-style signals.

Therefore, you'll need to rely more on listening to announcements and the familiar door closing chime to know when it's time to get moving again.

There's also another useful light to keep an eye out for - a blue one, which illuminates on the front carriages of some Circle, District, Hammersmith and City and Metropolitan trains. If the light (which is in the same position where it usually lights up white) turns blue, then this train is equipped with, and may be deploying, de-icing solution.

This generally means you have a better chance of reaching your destination on an especially chilly day.