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.