It won't be until December 2019 that the tunnelled section of the new Elizabeth Line will be fully open - and it won't be until May next year when the new line begins officially operating above ground in East London, between Shenfield and Liverpool Street.
But from today, you can already catch one of the new trains that will be serving on the line.
After months of testing, the first Class 345 train is now running passenger services on the rails of what is currently known as "TfL Rail" - the line that will eventually become the Elizabeth Line's eastern flank.
Catching the very first Elizabeth Line train out of Liverpool street. pic.twitter.com/2yNnNzLjQ3
— IanVisits (@ianvisits) June 22, 2017
The trains are built by Bombardier and will be able to hold up to 1500 passengers each (with 450 seated) and travel up to 90mph. The Elizabeth Line will eventually have 66 of them.
Welcome to the face of Crossrail! The first of the 66 Elizabeth Line trains in operation from today, starting with a journey to Shenfield pic.twitter.com/hoEX4bq32P
— Rachael Venables (@rachaelvenables) June 22, 2017
The trains are being built in Derby and perhaps notably, these are some of the first trains that are not legally required to be painted yellow at the front. This used to be a safety requirement, but recently regulations have been relaxed because trains have headlights.
Finally! I've been waiting for this since 1993! pic.twitter.com/PvFUOvMo8l
— Simon Bennett (@PsiBennett) June 22, 2017
It isn't clear whether the functionality has been activated yet, but the new trains will have wifi when the Elizabeth Line is up and running.
— Modern Railways (@Modern_Railways) June 22, 2017
So if you want to catch an Elizabeth Line train before anyone else today, head to your local TfL Rail station, and probably be prepared to wait for a while because so far there's only one of the new trains running.