A groundbreaking service sending instant Tube delay updates to commuters' phones is being launched today by Transport for London and Twitter.
The service alerts passengers to severe disruption on Underground and TfL rail lines as soon as they occur.
It has been described as a "world first" by TfL and will give passengers immediate notifications on their mobile phones as long as they opt-in.
The system is being released to the public today, although it is still undergoing testing.
Mayor of London Sadiq Khan said: "Like every Londoner I rely on public transport to get me around and this world-first service looks set to become an essential tool for millions of Tube passengers.
"It is an innovative way of providing people with live updates from the Underground and contributes to my goal of making it as easy as possible to get around the capital."
Anyone who follows any combination of four existing TfL Twitter feeds will be able to sign up for the instant notifications.
Currently, obtaining live travel information via Twitter means having to visit the relevant account or searching through your timeline for the latest tweets.
This is the first time that Twitter has partnered with a transport authority to provide live travel information in this way.
To opt in, customers need to visit http://tfl.gov.uk/twitter-alerts and select the lines for which they would like information.
