The first trains between London to Oxford ran today (Monday 12) as a multi-million pound rail project got under way.
Chiltern Railways' new Marylebone service set off at 7.20am after the final pieces of the track were installed in September.
It is expected that more than 850,000 journeys will be taken on the new route, which the company says "offers genuine competition".
The journey from London to Oxford will take 60 minutes.
Great Western Railway already runs a service between Oxford Parkway and London Paddington and will compete with the city centre route.
Transport Secretary, Chris Grayling, said: "This is the first new rail link between a major British city and the capital in 100 years and also a shining example of partnership working."
Annual season tickets between Oxford and London will cost £4,920 from 2 January following the annual price increase.
Network Rail chief executive Mark Carne said: "I am delighted that Network Rail has delivered the first part of East West Rail on time and on budget for our customers.
"What's really satisfying is how this happened. Chiltern told us what their customers wanted and put up some money - then Network Rail, working closely with Chiltern, made it happen."
The new line is the latest transport boost for the area, after the green light was given for Paddington to be transformed .
The scheme, which will see a new 14-storey building nicknamed The Cube and a massive revamp of Paddington station .
A total of £65m will be invested into the Network Rail station, which will include a new Bakerloo Tube station , with other highlights featuring offices, restaurants and a piazza complete with £2m of public art.
Keep up to date with the latest news in west London via the free getwestlondon app.
You can even set it to receive push notifications for all the breaking news in your area.