A new peak timetable will come into effect from 21 May, which TfL said would increase connectivity from both the east and west. Services will run all day between Shenfield in Essex to Heathrow Terminal 5 for the first time, with two trains an hour scheduled.
In the west, there will be an increase in peak services from Reading, with some trains previously operated by Great Western Railway becoming Elizabeth line services with reduced stops.
As a result, there will be more frequent services to and from Heathrow, with the airport receiving six Elizabeth line trains per house. All Heathrow trains stop at Terminals 2 and 3, with four per hour continuing on to Terminal 4, and a further two per hour continuing on to Terminal 5.
In addition, TfL said there would be improved Elizabeth line signage at Heathrow.
The new timetable will come into effect just a few days before TfL marks a year of the new line, which links Reading – via Heathrow, Paddington and central London – with east London and Essex.
"With this new timetable, those travelling through central London will have a train arriving around every two and a half minutes, those using Heathrow airport will have more regular services, and time will be shaved off many journeys from Reading, Heathrow and into central London," said London’s transport commissioner Andy Lord.
"Those on the east will also benefit from twice hourly services to the airport, linking Essex and west London on the line for the first time."
