Following funding from TfL, the Olympic Delivery Authority (ODA) and Network Rail, starting today (Monday 23) London Overground services from Richmond and Clapham Junction to Stratford will run four times an hour every day, increasing the total number between Willesden Junction and Stratford to eight trains per hour in the peak.

This is as well as four trains per hour every day on the Gospel Oak to Barking line and up to eight trains an hour between Highbury & Islington and Dalston Junction on the East London route.

It is the latest example to demonstrate that all 2012 transport improvements are on track to be delivered well ahead of the Games, delivering an early transport legacy for Londoners that will also be enjoyed for many years after 2012.

The new London Overground timetable is the result of the first major revamp of the line since 1869, which saw intensive civil engineering and complex signalling work take place in more than half of London’s boroughs. Network Rail upgraded and replaced more than 200 signals, renewed more than seven kilometres of track and 69 sets of points, lengthened 30 station platforms and carried out additional improvements at seven other stations.

The Mayor of London Boris Johnson, said: “London Overground is quite simply a huge rail success story for the Capital. Just over three year’s ago this network was one of Britain’s worst performing railways, run down and neglected. Now, it performs consistently in the top three of the nation’s rail league tables

“Transport for London (TfL) has set the standard and shown that the worst can be turned into one of the best with proper, well-managed investment. There is a brand new air-conditioned fleet with longer trains specially designed for London, there are cleaner, safer and well-staffed stations across the network and there is a vastly improved signalling and track network which makes it all run on time.

“As part of London’s Olympic Transport Network, this top performing railway is now also ready to play its part in next year’s Games as well as leave a legacy for passengers long after 2012.”

Mike Brown, Managing Director of TfL’s rail division which manages the railway, said: “The new timetable provides the high frequency, highly reliable, air conditioned service TfL promised when it took over the railway. Ridership is currently running at 55m passengers a year.

“London Overground is now providing a turn up and go service with direct links to the Tube network for parts of the Capital not previously well served by rail. When the South London extension is completed in 2012, London Overground will be a complete orbital network around our city.”

Hugh Sumner, Director of Transport for the Olympic Delivery Authority, said: “Spectators using the London Overground to get to and from sporting events across the capital will benefit from a service which will not only be more frequent, but also more spacious, comfortable and punctual.

“In addition to improvements made on the East London Line, upgrades to the North London Line will also play a key role during the Games in bypassing central London to get spectators to the Olympic Park. This investment is helping create a transport legacy long before the Games have even started.”

Robin Gisby, director of operations at Network Rail, said: "The London Overground network is a perfect example of how investment in rail can boost services for passengers and leave a legacy which will help support economic growth. The partnership we have in place with TfL is delivering results for London and we will continue working together to deliver a high performing and reliable railway in the capital, every day."

The £550m improvement programme includes a track and signalling programme which was funded with TfL as well as ODA, Network Rail the Department for Transport and Stratford City Implementation Group. TfL also funded the new train fleet and a station refurbishment programme.

London Overground ran 96.7per cent of its trains on time during March and 96.3 per cent in April, placing it second and first respectively in Network Rail’s national monthly performance survey. With almost 19 out of 20 (94.9%) trains arriving on time over the last twelve months – it has the highest annual figure for any train operator in the country.

The independent Passenger Focus survey, undertaken in autumn 2010, found that:

Eighty-five per cent of passengers are satisfied with London Overground service overall, up from 82 per cent the previous year. The average figure for South East rail services in 2010 was 83 per cent;

Seventy-four per cent were impressed with the frequency of London Overground trains, up by 14 per cent year on year;

Passengers satisfied with train punctuality rose to 76 per cent, up from 68 per cent in 2009;

Eighty-four per cent said they were satisfied with customer information during their journey, up a whopping 24 per cent on 2009 (65 per cent);

Average passenger satisfaction with the overall environment on the railway has increased by 13 per cent since TfL took it over from Silverlink - from 44 per cent in 2007 to 58 per cent now.

Fare evasion on the network has been reduced from 15% to 3% since TfL began managing the service.

Network Rail will require access to the network for maintenance work, during the less busy periods such as overnight or at weekends.

Network Rail will also require access to the tracks between Gospel Oak & Stratford every Sunday, the service will start after 9am on Sundays.

Since TfL created London Overground in 2007, £1.4bn has been invested in building the East London line route connecting Dalston Junction in the north with New Cross, Crystal Palace and West Croydon in the south in May 2010. This included building four new stations in Hackney. The East London line route was connected to the North London line route with a link between Dalston Junction and Highbury and Islington in February this year. A further extension in South London will be completed by the end of 2012.

A new fleet of 57 air-conditioned, high capacity trains has also been introduced across the network

All London Overground stations have been refurbished. This includes deep cleaning and painting, upgrading passenger information and CCTV systems, the installation of help points and platform improvements.