Page 547 - 360.revista de Alta Velocidad - Nº 6

Methodology to determine the optimal design speed in a High-Speed Line

Table 5: Commercial speed and combination of maximum design speed which
maximize the Economic NPVs.

The following can be highlighted:
a. The higher the commercial speed, the higher the socio-economic profitability of the project.
This increase is produced until certain commercial speed, above which the economic
profitability starts to decrease.

It can be said that, for each fare an optimal point in terms of economic profitability, which
correspond to a certain commercial speed is obtained. The results obtained, show: for a
tariff of 12c€/pkm the optimal (maximum economic profitability) is reached at 342km/h and
for a tariff of 20c€/pkm the optimal is obtained at 327km/h.
b. The economic profitability is reduced with the increase of the ticket price; this argument
is in line with (García Álvarez, González Franco, & Rubio García, 2015). The higher
the ticket price the lower the savings on external costs but the investment cost remains
constant.

c. There are some differences between financial profitability and economic profitability. The
higher the commercial speed, the higher the financial profitability of the project, in all cases
analysed (tariffs). As in the economic profitability, this increase is produced until certain
commercial speed, above which the financial profitability starts to decrease. It is seen that
this “optimum financial” is reached at commercial speed lower than the commercial speeds
that obtain the “optimum economic”.

d. Furthermore, the results obtained also show the combination of maximum speed which
should be built each sub-section. It can be observed, in order to obtain the optimal
commercial speed, the maximum design speed is always assigned to the flat terrain and the
minimal maximum design speed is allocated to the very mountainous terrain.

International Congress on High-speed Rail: Technologies and Long Term Impacts - Ciudad Real (Spain) - 25th anniversary Madrid-Sevilla corridor 545