Environmental Engineering Reference
In-Depth Information
growing demand. However, this cost may be considered negligible compared to the
cost of building new HSR lines. Typical investment cost of HSR line has been about
7 million Ecu per kilometre (MEcu/km) (CEC, 1995; Janic, 1999b). Consequently,
savings in infrastructure cost are in favour of APT, since the airport and air traffic
control infrastructure already exists, while the HSR network has to be built as a whole.
Operating costs
Operating costs of APT per unit of output (seat-km) are shown to be generally
higher than HSR, assuming that traffic volumes are sufficiently high to justify run-
ning HSR services. Moreover, for APT, this cost decreases with increase in travel dis-
tance, while it is approximately constant for HSR. Consequently, under such cir-
cumstances, in terms of potential savings, HSR appears to be preferable compared
with APT. Some typical values of operating costs of APT and HSR are 0.042 Ecu/
seat-km and 0.055 Ecu/seat-km, respectively (Janic, 1999b).
Energy consumption
Energy consumption has a different pattern for APT and HSR. For APT, it is higher
during take-off and climb-out, 'economically' acceptable at optimal cruising alti-
tudes, and less intensive while approaching and landing. Contrarily, energy con-
sumption for HSR is proportional to cruising speed. This means that it is lower
during the accelerating/decelerating phase of the trip and higher but constant dur-
ing cruising at maximum speed. Expressed per unit of output, energy consumption
per unit of output (seat-km) decreases more than proportionally for APT and is
roughly constant for HSR as route length increases. For example, on average, the
Airbus A 320-200 consumes 0.425 kilowatt hours per second-kilometre (kwh/s-km)
on the route of 300km, and 0.248kwh/s-km on the route of 1200km. On average,
the HS TGV train consumes between 0.106 and 0.141kwh/s-km on travel distances
between 200 and 1200km, respectively (ITA, 1991). As can be seen, with respect to the
savings of energy, HSR is favourable to APT on the whole range of travel distances.
User time-to-distance cost
User time-to-distance cost for APT decreases with increase in travel flight distance.
In such a case, users take the advantage of higher speed while cruising on longer dis-
tances in comparison to the relatively time-consuming procedures, which take place
at arrival and departure. For example, depending upon travel distance, the overall
speed may significantly vary between 400-800km/h (Geerlings, 1998; ITA, 1991;
Janic, 1993). However, this is not relevant while using HSR, particularly when there
are no intermediate stops along the line. The typical overall speed of HSR varies
between 250-300km/h. Consequently, savings in the time-to-distance cost are in
favour of HSR compared with APT on the shorter travel distances, and in favour of
APT compared with HSR on the long travel distances.
Noise
Noise has also a quite different pattern for APT and HSR. For APT, noise emission
is very high in the vicinity of airports during landing and taking-off, and generally
has a negligible impact while cruising. For HSR, the level of noise increases with
increase in speed and can be heard along the whole line as the train passes by. Typi-
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