Page 297 - 360.revista de Alta Velocidad - Nº 5

Reducing High-Speed Rail Costs by Combined Double-Single Tracks

Therefore, with all this information, i.e. construction cost, services, speed and proposed
schedule, the optimization program calculates which segment should be designed in single- or
double- track, in order to define the most cost-effective solution.
The results of the analysis are shown in Table 8 where, in addition to the previously mentioned
5 alternatives, there are two more proposals: Alternative 0, that is, the “No action alternative”
that plans to maintain the current line, and Alternative 6, that is, the “Double track alternative”,
i.e all line in double track. It should be noted that the optimization program has not considered
necessary this alternative despite of the high number of 116 circulating services.
Table 8. ADST alternatives for Vitoria-Zaragoza case

It is convenient to highlight that, with a relative time of 1.00, which means optimal relative
time for the high-speed services, the construction cost of the infrastructure is still a 30% (390,8
M€) cheaper than the double track proposal.

2.2.4 Rational investment analysis

Subsequently, with the aim of defining the optimal multi-criteria solution, a rational investment
assessment is developed, in which all the alternatives are considered under an economic, social
and quality points of view. The criteria to define the multi-criteria evaluation is defined in
subsection 2.1.4, where 50% is the economical approach and the other 50% considers the social
benefits. This kind of analysis is essential because these infrastructure constructions have
two different perspectives, thus the cost-benefit analysis is fundamental in the short-term
economic development, while technical indexes reflect the social benefits which are achieved
in a medium and long term.

Therefore, in this case, the same indexes explained in subsection 2.1.4 have been used, except
for parameter (d) of the Technical indicator, because in this case it is the Environmental Index,
IE.
IE is a quality index whose objective is to benefit in the weighting the alternatives that optimize
the route scheme against possible future actions to satisfy higher demands. To achieve this,
which fraction of common line between the routes Zaragoza - Vitoria and Zaragoza – Pamplona
is measured, that is to say, those with noticeably greater demand, is projected in double-track.
In this way, it is possible to satisfy a series of premises:

International Congress on High-speed Rail: Technologies and Long Term Impacts - Ciudad Real (Spain) - 25th anniversary Madrid-Sevilla corridor 295