Transport for London (TfL) is planning to launch a new application programming interface (API) next year to help developers utilise the organisation's open-source travel data. 

Several mobile apps and websites draw on TfL’s publicly-available datasets but some developers have criticised the complexity of working with TfL's data, saying it is presented in unfamiliar formats. 

TfL head of online Phil Young told Techworld: ““To make it easier for developers to work with this data we are preparing a new single API for launch in 2014. This will provide normalised data across transport modes and allow faster development of new services.

"Where possible TfL's open data follows recognised standards such as NAPTAN and TransXchange. As a multimodal transport authority our data comes from a wide variety of systems, which leads to some variations in data sets between feeds."

Citymapper - a travel app founded by former Google employee Azmat Yusuf – uses TfL’s data to deliver its app, which is the third most popular free navigation app in the iTunes store after Google Maps and NavFree, despite only covering one city in the UK.

Last month, entrepreneur Yusuf said that TfL’s data can be harder to work with than that offered by other cities because it's presented in a different format to the most widely used standard. 

Responding to Yusuf's comments, TfL CIO Steve Townsend said: “They’d be right, we could shape it and we could put different standards around it. We basically say this is all the information we have, it’s public data, utilise it in the way you want to.

"If there was a valid reason for TfL to change the shape of that data, and it was financially acceptable to the organisation, in that it would assist with fares or maintenance regimes, then there’s no reason that conversation couldn’t be had.

“But the developer world, as they very well know when you go and speak to them, are very demanding in what they want.”

While Yusuf said TfL’s data was difficult to work with in some respects, he praised the organisation for the amount of live data it offers compared to other cities. This enables Citymapper to introduce a range of live features, such as alerting users to issues on their favourite tube line or showing crosses next to tube stations that are experiencing problems.