We are now moving towards delivering on our accessibility commitments
This will more than double the number of step-free stations on the Underground.
LU also confirmed that it is on schedule to deliver on its commitment to make 25 per cent of stations step-free by 2010.
The improvements are funded by Transport for London's (TfL's)£10bn 5-Year Investment Programme.
Speaking at the Disability Capital conference, LU Managing Director Tim O'Toole said: "London Underground is investing more than ever before to make the Tube as accessible as possible as quickly as possible for all customers.
"By 2010, 25 per cent of Tube stations will have step-free access and this will increase to one third of all stations by 2013.
"Where necessary, works will be prioritised to ensure that as many stations as possible serving Olympic venues have step-free access for the 2012 Games.
"Significant progress has been made during the past year. Feasibility studies to improve accessibility have been completed at 90 stations allowing LU to understand the extent of the engineering works that need to take place.
"We are now moving towards delivering on our accessibility commitments with work currently underway at four stations."
St. Pancras mainline station supported by King's Cross St. Pancras Underground station will have a key role to play in getting people to and from the main Olympic site at Stratford site via the high-speed Olympic Javelin service during the 2012 Games.
The station is the Tube's busiest and most congested with 84 million passengers each year and the Government is funding the extensive redevelopment of the Underground station.
The new Western Ticket Hall will open later this year while the Northern Ticket Hall opens in 2010.
The opening of the Western Ticket Hall will make the Metropolitan and Circle line platforms accessible while the opening of the Northern Ticket Hall will mean that all ten platforms serving the Circle, Hammersmith & City, Metropolitan, Northern, Piccadilly and Victoria lines will be fully accessible in good time for the Olympics.
Currently 45 stations out of 275 have step-free access from street to platform with work underway on a further four.
The prioritisation of which stations are to be made accessible is focussed on both the number of step-free journeys that individual stations would make possible as well as demographic information relating to where our disabled, elderly and mobility impaired customers live, and where they would like to travel to.
Tim O'Toole continued: "Many stations do not currently meet the needs of customers with physical, hearing or visual impairments.
"All 253 LU-owned stations are due to be refurbished and modernised by 2011 and accessibility features will be added to each station.
"Accessibility is about more than simply-step free access and features such as induction loops, tactile paving and additional and more visible help and information points will be added to stations as modernisations and refurbishments are completed."
LU is also replacing and refurbishing its train fleet.
The entire District line fleet is currently being refurbished to include the provision of multi-purpose areas capable of accommodating wheelchair users and on board dot matrix indicators.
The Victoria and sub-surface lines will be getting brand new trains from 2009 onwards and accessibility will be a key feature.
New and refurbished trains are an important element in increasing accessibility.
To improve accessibility, every new or refurbished train will have destination information in both audible and visual format and audible and visual warnings will be given to indicate closing doors.
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