These are based on time savings of 20 minutes from 2003-2007 and for the whole assessment period for Waterloo passengers, who will only benefit from Section 1 time savings. One third of trains/passengers are assumed by the Department to use Waterloo after Section 2 opens. The Department and the National Audit Office assumed different levels of time savings for Section 2. The assessment of time savings has changed as the specification of the Link developed, reflecting time tabling assessments of running speeds, stopping patterns and the Link's operational capacity. The Department's estimate of time savings was based on an engineering assessment from July 1996, which concluded that Section 1 would deliver a time saving of 20 minutes, and Section 2 a further time saving of 19 minutes. Only two thirds of passengers were assumed to benefit from the Section 2 time saving, therefore, the Department used a weighted time saving of 30 minutes for all passengers.
The National Audit Office calculations assumed time savings for Section 2 of 13 minutes, and total time savings of 33 minutes for St. Pancras passengers from 2007 onwards. This was consistent with LCR's assumptions in the "LCR Key Assumptions Book" of June 1998, when the restructured deal was announced. The Department has now told us that the latest Section 2 timetables have revised average time savings from Section 2 of 17.5 minutes.
Value of time growth assumptions have been corrected. The growth rate was 2.4% a year in the Department's version. We have used the growth rates in the Department's guidance note, Highways Economics Note 2: ie 2.07% until 2016, and 2.21% a year thereafter.19 For time savings and capacity benefits the rule of half applies, so those "existing passengers" (ie up to 19.2 million) get the full benefit (Appendix 7, Figure 44). Those above that only get half of the benefit.
__________________________________________________________________________________________________
19 Highways Economics Note 2 is used as guidance in the appraisal of road schemes. The rate of growth of the value of time in the note applies to the whole economy so is also applicable in the case of the Link.