Page 260 - 360.revista de Alta Velocidad - Nº 5

Jiménez, Pablo Lorenzo. Zamorano, Clara Isabel. Escobar, Adrián. Escobar, Jorge.

Within their analyses, Smith et al. (2016), and Smith et al. (2017) use these methods to determine
the damage produced by each type of train traveling through the study sections.

4.2.3 Cost allocation

The cost allocation method can be defined as a hybrid between both methods (Nielsen et
al., 2016). Smith et al. (2016), and Smith et al. (2017) employ hybrid methods, with
both economics and engineering analysis. These studies start from the idea that it is
difficult to implement methods that, by means of a single step, econometric or engineer,
is useful to determine the correspondence between costs and damages. For this reason, it
is necessary to use methods with both econometric and engineering approaches.

It should be noted that, in these methods, the amount paid for maintenance in previous
years, is considered to be produced by the different sources of damages. This has a
problem, as it implicitly assumes the hypothesis that it covers the maintenance needs of the
period. It is normal that, in situations of budget shortages, a certain maintenance deficit
is generated, which in turn causes losses of the patrimonial value of the infrastructures.

5. Proposal for a new methodology

As it has been stated the models developed for the moment may have an econometric
approach, an engineering approach, or a combination of both. The general idea from
this methodology proposal is that it would be advisable to integrate asset management
systems with charges calculation. This proposal, based on asset management systems,
could be classified as a mixed proposal, as seen in the previous section, as it encompasses
an engineering and economics approach.

Beginning with an initial estimate of maintenance costs based on the experience of
infrastructure managers, the continuous use of these systems over several years would
allow these costs to be fine-tuned until a good correlation between the forecast and the
actual cost incurred is found.

To do this, the data of train measurements and asset management systems would be used
to determine the condition of the track and the maintenance needs generated between
two successive passes of the measurement trains. The steps would be:

1. The measurement data would allow to evaluate the damages that have occurred
between t two successive passes. To do this, the asset management strategy should
define what would be the minimum frequency of passing for the measurement
trains.

2. The asset management system uses these data, and cross-matches them with data
on expected traffic, age of elements, etc., to generate an estimate of the annual
maintenance costs, as well as the replacement rates. Here, it is important to
consider that we must separate the costs associated with the elements that present
a wear and tear on the traffic (susceptible, therefore, of a direct cost), of those
that do not have wear associated with traffic directly.

3. A fundamental aspect is to make a division of the infrastructure in homogeneous
sections depending on its characteristics and traffic, to obtain comparable data

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