They are all scaled from 0 to 100 and scores are derived from annual surveys conducted among Londoners or users of particular parts of the transport system (as appropriate). The six indicators are: 1) public transport customer satisfaction; 2) public transport crowding (satisfaction indicator); 3) road user customer satisfaction; 4) perception of journey experience; 5) perception of noise; 6) perception of the urban realm. It is expressed as a percentage score.