National Public Transport Access Node database (NaPTAN)

NaPTAN provides a unique identifier for every point of access to public transport in the UK, together with meaningful text descriptions of the stop point and its location. This enables both computerised transport systems and the general public to find and reference the stop unambiguously. Stops can be related to topographic regions via the National Public Transport Gazetteer. (From the overview)

On 2010-03-22 NAPTAN was announced as open data in a speech by Gordon Brown.

A subset of the NaPTAN data is available on Open Street Map. See the uk-naptan-osm package.