Underground Environment

HC Deb 27 November 2001 vol 375 cc750-1W

Mr. Page

To ask the Secretary of State for Transport, Local Government and the Regions if he will make a statement on the formulas(a) stated for the calculation of the state of the Underground environment as follows:

what each of the letters stand for; where it is a value, how that value is calculated; and what methods were used in the formulas' production. [17123]

Mr. Jamieson

[holding answer 22 November 2001]: (a) The formula the hon. Member refers to is a weighted average of scores for different aspects of the passenger environment. The PPP contracts refer to this environment, which is an important part of the infrastructure companies' performance, as Ambience.

The letters in the formula represent: A—is the total ambience score, which is calculated each quarter and used to adjust the payments London Underground makes to the infrastructure companies. Total Ambience covers both trains and stations on all lines for which an infrastructure company is responsible. QASAS_js—is the quarterly average survey score for a particular aspect of Ambience, such as the level of litter or graffiti, at a particular station. QATAS_jL—is the quarterly survey score for similar aspects of Ambience on trains on a particular line. QATAS_kL—is the quarterly score for specific aspects of Ambience on trains that are measured according to engineering techniques rather than surveys, for example smoothness of ride and on-train noise. W^s_js.W^T_jL,W^T_kL—are the weights applied by London Underground to these various scores in order to calculate the weighted average.

In each case the letter used in the formula represent values. The scores are calculated primarily from periodic surveys undertaken by mystery shoppers, a technique for measuring Ambience that London Underground has used for a number of years and which has been adapted for the PPP contracts. Where appropriate, some scores are calculated from engineering tests. The weights are fixed values, set out in the contracts, which have been derived from London Underground's customer research.

(b) The formula referred to is a weighted average of the Ambience scores for trains only. Under the PPP contracts, the infrastructure companies are measured according to the level of Ambience on trains and stations separately, as well as according to the total level of Ambience on the lines for which they are responsible.

The letters in the formula represent: TMS—is the train Ambience score, which is calculated each quarter. QATAS_j—is the quarterly average survey score for a particular aspect of Ambience, such as the level of litter or graffiti, on trains. QATAS_k—is the quarterly score for specific aspects of Ambience on trains that are measured according to engineering techniques rather than surveys, for example smoothness of ride and on-train noise. W^T_j,WT_k—are the weights applied by London Underground to these various scores in order to calculate the weighted average.

In each case the letters used in the formula represent values. The scores are calculated primarily from periodic surveys undertaken by mystery shoppers, a technique for measuring Ambience that London Underground has used for a number of years and which has been adapted for the PPP contracts. Where appropriate, some scores are calculated from engineering tests. The weights are fixed values, set out in the contracts, which have been derived from London Underground's customer research.