Transport for London (TfL) has had to suspend access to the underground train departure data after demand for the feed overloaded the organisation's gateway system.

The data was made available on 15 June to third-party application developers keen to market what is a precious information resource to London travellers, but demand through the London Datastore proxy has exceeded expectations in a matter of days.

From an initial 180,000 requests, traffic soared to 10 million hits per week, overloading servers, the organisation said TfL has now suspended the service temporarily until the system can be redesigned.

“We are really encouraged that the feed to our Tube departure information is so popular and TfL is doing everything to restore it as soon as possible but this may take some time, said London Underground's Steve Townsend.  “We’re sorry for the temporary disruption to this API Beta feed and we will provide an update as soon as we have further information.”

The train departure information is part of a number of data sets being made available to third parties, including station locations, places to buy Oyster smartcards, and live traffic cameras. Bus stops and bus routes are being added.

The market for this data is potentially huge as developers compete to create the best Android smartphone and iPhone apps. Much work remains, however, not only in servicing the huge interest in the data but in improving its quality.