Energy 36 (2011) 6577e6582
Contents lists available at SciVerse ScienceDirect
Energy
journal homepage: www.elsevier.com/locate/energy
Study on the maximum operation speeds of metro trains for energy saving as well
as transport efficiency improvement
Xuesong Fenga, b, *, Baohua Maoa, b, Xujie Fenga, Jia Fenga
a
b
Integrated Transport Research Center of China, Beijing Jiaotong University, No.3 Shangyuancun, Haidian District, Beijing 100044, PR China
School of Traffic and Transportation, Beijing Jiaotong University, No.3 Shangyuancun, Haidian District, Beijing 100044, PR China
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 27 April 2011
Accepted 4 September 2011
Available online 5 October 2011
By following a computer-aided simulation procedure, this research analyzes the traction energy cost and
transport operation time per 10,000 passenger-kilometers of two representative types of metro trains in
China under various top speeds between different stations along a hypothetically straight and smooth
metro line, from the perspective of both energy saving and transport efficiency improvement in
consideration of multi-factors. It is empirically confirmed that if the transport distance between stops is
shorter than 1,800 m, the metro trains should set their maximum speeds lower than 70 km/h but higher
than 30 km/h. And a shorter stop-spacing requires a lower maximum speed in this speed range to get the
least costs of energy and time. The exact value of the maximum speed in this speed range ought to be
further determined based on the integrated performances of the train’s passenger capacity, engines,
streamline body design, etc. If the transport distance is longer than 1,800 m, the generalized expense of
energy and time per 10,000 passenger-kilometers decreases with the increase of the maximum speed of
a train. Nevertheless, such decreases become very slow when the maximum speeds of the trains exceed
70 km/h.
Ó 2011 Elsevier Ltd. All rights reserved.
Keywords:
Metro electrical multiple unit
Maximum operation speed
Transport distance between stops
Computer-aided simulation
Transport efficiency
Energy cost
1. Introduction
Since the 2008 Olympic Games held in Beijing, urban rail
transports have developed quickly in some big cities of China. Till
the end of 2009, the lengths of the urban rail transit lines in Beijing
and Shanghai have respectively exceeded 228 km and 343 km [1].
And most of them are rapid transit metro lines. Because the traction
force of a train increases with the improvement of its maximum
speed [2e6], big traction forces owing to high speeds consume
more energy for the same transport work [7e11]. Therefore, metro
trains running with comparatively high maximum speeds (e.g. over
80 km/h) transport passengers more efficiently in comparison to
the transport services provided by the metro trains operating with
relatively low maximum speeds (e.g. around 50 km/h), but
Abbreviations: EC, European Communities; EMU, Electrical Multiple Unit;
EMU-A, EMU type-A; EMU-B, EMU type-B; GDP, Gross Domestic Product; IFEU,
Institut für Energieund Umweltforschung Heidelberg GmbH; p-km, passengerkilometers; TEC, Traction Energy Cost; TOC, Technical Operation Cost; TOT,
Technical Operation Time.
* Corresponding author. School of Traffic and Transportation, Beijing Jiaotong
University, No.3 Shangyuancun, Haidian District, Beijing 100044, PR China.
Tel./fax: þ86 (0) 10 51684208.
E-mail addresses: [email protected], [email protected] (Xuesong Feng).
0360-5442/$ e see front matter Ó 2011 Elsevier Ltd. All rights reserved.
doi:10.1016/j.energy.2011.09.004
meanwhile the high-speed metro trains consume electrical energy
more intensively. As a result, it has to be asked how the target topspeed of a metro Electrical Multiple Unit (EMU) can be reasonably
determined in view of both energy saving and transport efficiency
improvement, meanwhile by taking into account the effect of
multi-factors such as transport distances between stops, types of
the EMUs, and so on.
In fact, many researchers and practitioners have been continually making effort to interpret both the relationship between
different types of trains’ maximum speeds and corresponding
intensities of traction energy costs [12e16] and the relationship
between these trains’ top-speeds and their transport efficiencies
[17e20]. However, valuable research findings from exemplifications which are in practice incompletely examined by previous
studies still cannot systematically answer the above-raised question in a comprehensive manner. Based on the computer-aided
simulations of the passenger transports by two types of EMUs in
China, i.e. EMU type-A (EMU-A) and EMU type-B (EMU-B), on
a hypothetically straight and smooth metro rail line, this study tries
to propose a key to the above-asked question.
The contents of this paper are organized as follows. The
computer-aided simulation method adopted in this work to
compute a metro EMU’s Traction Energy Cost (TEC) (i.e. energy
consumed by traction and braking) and Technical Operation Time
6578
X. Feng et al. / Energy 36 (2011) 6577e6582
(TOT) (i.e. travel time excluding the time expended by stops in
stations) is first explained in Section 2. Next, Section 3 and Section 4
calculate the TEC per 10,000 passenger-kilometers (p-km) and TOT
per 10,000 p-km of a metro train running with different maximum
speeds between different stops by following the simulation method
explained in Section 2. Thereafter, on the basis of the studies made
in Section 3 and Section 4, a key to the above-asked question is
proposed in Section 5 by introducing the variable of Technical
Operation Cost (TOC) per 10,000 p-km. Finally, Section 6 draws the
conclusions, makes some suggestions for the metro transport
operations and points out some issues in future research.
2. Procedure of TEC and TOT calculations
By referring to the previous works [2e4,6,21,22], the computeraided simulation method presented in Fig. 1 is utilized to calculate
the TEC and TOT of a metro EMU starting with its full traction power
towards its target speed. As shown in this figure, the traction force
of the EMU in a calculation interval is first interpretable according
to the operating condition (i.e. coasting, being in traction, braking,
or others), the speed and the traction performance curves (which
are decided by the EMU’s type) of the EMU and the condition of the
rail line (e.g. gradients of ramps, radians of bends, and so on). And
the EMU’s TEC in this calculation interval is subsequently
computable based on the EMU’s traction force, speed and operating
condition. Finally, the TEC in each calculation interval is summed
into the total TEC of the transport by the EMU between stops, and
also the EMU’s TOT is able to be calculated by summation of the
simulation intervals. In this study, the EMU is assumed to transport
on a straight and smooth rail line. In other words, the traction
forces of the EMU are determined by the EMU’s traction performance curves and its speeds and operating conditions in calculation intervals.
3. TEC per unit transport
where,
evij : TEC per 10,000 p-km of the transport by an EMU with the
maximum speed of v from station i to station j, Unit: kWh/
10,000 p-km,
Eijv : TEC of the transport by an EMU with the maximum speed of
v from station i to station j, Unit: kWh,
Pijv : Full number of passengers in an EMU running with the
maximum speed of v from station i to station j,
Rvij : Ratio of the actual number of passengers to the full number
of passengers in an EMU running with the maximum speed of v
from station i to station j, and
Dij : Distance of the transport by an EMU from station i to station
j, Unit: 10,000 km.
The full numbers of the passengers are 1860 and 1398 in respectively the studied EMU-A and EMU-B which are both loaded with 6
passengers per square meter. The transport distance (Unit: 10,000 km)
from the nth stop (S(n)) to the (nþ1)th stop (S(nþ1)) (n ¼ 1,2,..,49)
of the hypothetic metro rail line in this research is represented by
Eq. (2) without counting the lengths of this rail line in stations.
DSðnÞSðnþ1Þ ¼ 2:00 105 ðn þ 1Þ
On the assumption that the EMU-A and the EMU-B are both fully
loaded, the changes of the TECs per 10,000 p-km of their transports
with the increase of their target maximum speeds between stops
are revealed in Fig. 2 and Fig. 3 respectively.
It is found in Fig. 2 that when the EMU-A’s maximum speed is
lower than 35 km/h, the difference of the TECs per 10,000 p-km is
comparatively small for different transport distances between
stops. Approximately 150 kW h at most is used in an extra manner
per 10,000 p-km for the same top speed, due to the decrease of the
transport distance between stops. Nevertheless, it is notable at this
time that the transport distances longer than about 1,800 m make
the TECs per 10,000 p-km decrease with the increase of the EMU’s
target speed. Furthermore, the decrease of the TEC per unit transport in this stage with the improvement of the maximum speed
For the purpose of evaluating TEC in view of passenger transport
workload, the TEC per 10,000 p-km of the transport by a metro
EMU with a maximum speed of v between its stops is defined by Eq.
(1).
evij ¼
Eijv
Pijv
Rvij Dij
Fig. 1. TEC and TOT Calculation Procedure.
(2)
(1)
Fig. 2. TECs of the EMU-A’s transports.
X. Feng et al. / Energy 36 (2011) 6577e6582
Fig. 3. TECs of the EMU-B’s transports.
becomes quickly in a relative manner if the transport distance
between stops increases. However, such decreases of the TECs per
10,000 p-km are very small. In contrast, the transport distances
shorter than around 1,800 m at this time cause the TECs per 10,000
p-km increase obviously with the improvement of the EMU’s top
speed. Moreover, the increase of the TEC per unit transport with the
improvement of the maximum speed accelerates with the decrease
of the transport distance between stops. While the EMU-A’s
maximum speed becomes higher than 35 km/h but still lower than
70 km/h, the TECs per 10,000 p-km of the transports for all the
distances increase with the improvement of the EMU’s maximum
speed. In comparison to the situations when the EMU’s maximum
speed is lower than 35 km/h, the additional energy cost per 10,000
p-km for a stop-spacing shorter than 1,800 m further increases
with the decrease of the transport distance between stops and the
improvement of the metro train’s maximum speed. The additional
consumption of electrical energy per 10,000 p-km for the stopspacing of 400 m in comparison to the energy cost for the transport distance of 1,800 m between stops increases from about
150 kW h while the EMU-A’s maximum operation speed is 35 km/h
to approximately 280 kW h when the EMU-A’s top speed is
increased to 70 km/h. If the EMU-A’s maximum speed exceeds
70 km/h, the increases of the TECs per 10,000 p-km stop when the
transport distances between stations cease the EMU’s acceleration
before its arriving at the next station.
It is somewhat different to the above-explained changes of the
EMU-A’s TECs per 10,000 p-km that if the maximum speed of the
EMU-B is no higher than 70 km/h, its TEC per 10,000 p-km is
increased for the same maximum speed because of the decrease of
the transport distance between stops, and such an increase of the
energy consumption accelerates with the decrease of the transport
distance and the improvement of the EMU’s maximum speed,
especially for the stop-spacings shorter than 1,800 m. While the
maximum speed of the EMU-B increases from 15 km/h to 70 km/h,
the additional energy consumption per 10,000 p-km for the stopspacing of 400 m in comparison to the energy cost for the transport
distance of 1,800 m between stops increases from around 50 kW h to
6579
more than 350 kW h. In this process, the increases of the TECs per
10,000 p-km because of the decreases of transport distances between
stops are relatively small for the same top speed lower than 25 km/h,
and the increases of the TECs per 10,000 p-km with the improvement
of the EMU’s maximum speed till 25 km/h are comparatively slow. It
is similar to the changes of the EMU-A’s TECs per 10,000 p-km that if
the EMU-B’s maximum speed is continually improved from 70 km/h,
comparatively short transport distances between stations cease the
increases of the TECs per 10,000 p-km, because the EMU cannot be
accelerated any more before arriving at next stops.
Now it is clarified that the TEC per unit transport of a metro EMU
is much concerned with its target speed, transport distance
between stops and integrated performance of engines, streamline
body design, passenger capacity and so on for a certain load factor.
The TEC per unit transport of an EMU increases with its maximum
speed’s improvement. The reachable maximum speed by the EMU
decreases with shortening the transport distance between stops. It
is empirically confirmed that, for the transport distances no longer
than 1,800 m, the TEC per 10,000 p-km of a metro EMU with
a certain maximum speed increases in an accelerating scale with
the decrease of the EMU’s transport distance between stops.
Meanwhile, such an increase of the TEC per 10,000 p-km accelerates with the improvement of the EMU’s maximum speed. If the
transport distances between stops exceed 1,800 m, there is almost
no influence of the transport distances upon the TEC per unit
transport. It is manifested that transport distance between stops is
a very important factor of a metro EMU’s TEC especially for its
comparatively high-speed transport operations, as ever partially
illustrated by examples of, in other words, times of a train’s stops in
the works of e.g. EC [23], IFEU [24] and Ding and Mori [25].
Moreover, the integrated performance of the metro EMU’s engines,
design of streamline body, passenger capacity and so on also plays
an essential role for the TEC per unit transport.
4. TOT per unit transport
It is proved that a metro EMU’s TEC per unit transport is basically
increased with the increase of the EMU’s maximum speed. And it
seems rational that transport as slow as possible is the most energy
saving way in the viewpoint of sustainability. But such a conclusion
neglects the importance of improving transport efficiency.
The TOT per 10,000 p-km of the passenger transport by a metro
EMU with a maximum speed of v between stops is defined by Eq.
(3) so as to estimate its passenger transport efficiency from the
perspective of transport operation.
tijv ¼
Tijv
Pijv
Rvij Dij
(3)
where,
tijv : TOT per 10,000 p-km of the EMU running with the maximum
speed of v from station i to station j, Unit: h/10,000 p-km, and
Tijv : TOT of the EMU running with the maximum speed of v from
station i to station j, Unit: h.
Also in the hypothesis of 6 passengers utilizing one square
meter of the car floor of both the EMU-A and the EMU-B, the
changes of the TOTs per 10,000 p-km of the transports between
stops along the afore-explained hypothetical metro rail line by
these two types of EMUs with the increases of their maximum
speeds are presented in Fig. 4 and Fig. 5 respectively.
It is obviously shown in these two figures that the TOTs per
10,000 p-km of the transports by the EMU-A as well as the EMU-B
for various distances between stops decrease overall with the
6580
X. Feng et al. / Energy 36 (2011) 6577e6582
Fig. 4. TOTs of the EMU-A’s transports.
increases of the EMUs’ maximum speeds. When the maximum
speeds are below 30 km/h, the TOTs per 10,000 p-km decrease
sharply with the increases of the top speeds of the EMUs. And the
decrease of the TOT per 10,000 p-km owing to the increase of
transport distance between stops is very small for the same
maximum speed in this phase. While the maximum speeds of the
EMUs increase from 30 km/h to 70 km/h, the decreases of the TOTs
per 10,000 p-km with the increase of the target speed for different
transport distances between stops become much slow, and the
additional consumptions of the TOTs per 10,000 p-km for the same
maximum speed due to the decreases of transport distances
between stops increase in an expanding scale for the continual
decreases of the transport distances in the same degree. Moreover,
such increases of the TOTs per 10,000 p-km because of the
decreases of the transport distances at this time accelerate with the
improvements of the maximum speeds of the EMUs. If the
maximum operation speeds of the EMUs are set to be over 70 km/h,
short transport distances between stops more quickly stop the
decrease of the TOT per 10,000 p-km with the increase of the
maximum speed, because the EMUs have to start their decelerations sometime before reaching their speed targets in order to be
enabled to stop in security at the next station.
Now it is acknowledged that for a certain area utilization ratio of
the car floors, the efficiency of the transport by a metro EMU
increases with the improvement of the EMU’s maximum speed. The
increase of the stop-spacing’s distance is significant to improve the
EMU’s transport efficiency especially when the maximum speed is
comparatively big, as ever exemplified by e.g. van Wee et al. [26] and
Lindgreen and Sorenson [27] from a different perspective of times of
a train’s stops. It is also explained by the contents shown in Figs. 4
and 5 that because the characteristics of engines, designs of
streamline bodies, passenger capacities, etc. of various types of EMUs
are somewhat different, the upper and lower limits of the TOTs per
10,000 p-km of the transports by the EMU-A and the EMU-B are
accordingly different in some degree, though the changes of the TOTs
per 10,000 p-km with the increases of the maximum speeds of these
two types of EMUs follow the same general trend. It is found that the
integrated performance of an EMU’s various elements is another
factor to determine the EMU’s transport efficiency.
5. TOC per unit transport
In order to consider both energy saving and transport operation
efficiency improvement, the TOC per 10,000 p-km of passenger
transport by a metro EMU with a maximum speed of v between
stops is defined by Eq. (4) to propose a key to the question raised at
the beginning of this paper, based on the afore-studied TEC and
TOT.
cvij ¼ a evij þ b tijv
(4)
where,
cvij : TOC per 10,000 p-km of the EMU running with the
maximum speed of v from station i to station j, Unit: Yuan RMB/
10,000 p-km, and
a,b: Coefficients whose values need to be decided respectively
according to the unit price of energy consumption and the Eq.
(5) from the aggregate perspective of all the passengers’ unit
time values consumed by the transport.
b¼
Fig. 5. TOTs of the EMU-B’s transports.
GDP c;y
Pijv Rvij
365 24
(5)
where, GDPc,y means the annual Gross Domestic Product (GDP) per
capita, Unit: Yuan RMB.
The average unit price of the electrical energy consumptions for
railway transports is about 1.00 Yuan RMB per kWh in China. The
annual GDP per capita in 2009 is 25,575 Yuan RMB in China [1]. The
changes of the TOCs per 10,000 p-km of the transports by the
EMU-A and the EMU-B with the increases of their target speeds for
various transport distances between stops are shown in Fig. 6 and
Fig. 7 respectively.
X. Feng et al. / Energy 36 (2011) 6577e6582
Fig. 6. TOCs of the EMU-A’s transports.
It is evidently shown in both of these two figures that if an
EMU’s maximum speed is lower than 30 km/h, the TOCs per 10,000
p-km for different transport distances between stops decrease very
fast with the increase of the EMU’s maximum speed. And the effect
of the transport distance between stops on the TOC per 10,000
p-km is very small for the same maximum speed at this time. When
the maximum speeds of the EMUs increase over 30 km/h, especially
Fig. 7. TOCs of the EMU-B’s transports.
6581
for the transport distance no longer than 1,800 m, the TOC per
10,000 p-km for the same maximum speed is increased with the
decrease of the transport distance between stops. And such additional consumption is further enhanced with the increase of the
maximum speed. For instance, while the EMU-A and the EMU-B
takes the maximum speed of 30 km/h, the TOC per 10,000 p-km
for the transport distance of 1,000 m(¼1,600 m 600 m) from
station S4 to station S5 adds less than 4% in comparison to the TOC
per 10,000 p-km for the transport distance of 1,600 m from station
S7 to station S8; nevertheless, the TOC per 10,000 p-km for the
transport distance of 400 m(¼1,000 m 600 m) from station S1 to
station S2 increases almost 20% in comparison to the TOC per
10,000 p-km for the transport distance of 1,000 m from station S4
to station S5. Moreover, the increased ratio of the additional energy
consumption due to shortening transport distance from 1,600 m to
400 m rises from about 25% at the maximum speed of 30 km/h to
nearly 100% at the maximum speed of 70 km/h. In this stage, there
are almost no differences of the comparatively slow decreases of
the TOCs per 10,000 p-km with the increase of the maximum
speed, if the transport distances between stops are longer than
1,800 m. However, the TOCs per 10,000 p-km for the transport
distances shorter than 1,800 m continue their decreases in an even
slow manner with the increase of the maximum speed till the
maximum speed achieves some certain values able to make the
TOCs per 10,000 p-km get the least values for respectively each of
these transport distances. If the maximum speeds of the EMUs for
different transport distances below 1,800 m exceed such suitable
values, the TOCs per 10,000 p-km start to increase with the
maximum speeds’ improvements till the limitations from transport
distances effect stops of their increases.
It is revealed in both Figs. 6 and 7 that if a stop-spacing is
shorter than 1,800, the value of the maximum speed to realize the
least TOC per 10,000 p-km decreases in the range from 30 km/h to
70 km/h with the decrease of the transport distance between
stops. For example, as shown in Fig. 6, the maximum speed of
approximately 50 km/h adopted by the EMU-A makes the TOC per
10,000 p-km for the transport distance of 400 m from station S1 to
station S2 get the least value of about 1100 Yuan RMB, and the
least value of the TOC per 10,000 p-km for the transport distance
of 800 m from station S3 to station S4 is realized to be some 800
Yuan RMB by the maximum speed of about 65 km/h. In contrast,
the corresponding values of the maximum speeds adopted by the
EMU-B to achieve its least TOCs per 10,000 p-km for the transport
distances of 400 m and 800 m are respectively 45 km/h and
60 km/h, as presented in Fig. 7. The difference of the suitable
maximum speeds to actualize the least TOCs per 10,000 p-km by
different EMUs for the same stop-spacing is caused by the various
integrated performances of the EMUs’ passenger capacities,
engines, streamline body designs, etc.
According to the changes of the TOCs per unit transport with the
increases of the maximum speeds of the EMU-A and the EMU-B, it
is justified that in consideration of both energy saving and transport efficiency improvement, the target maximum operation speed
of a metro EMU for a transport distance shorter than 1,800 m
should be higher than 30 km/h and lower than 70 km/h. At the
same time, comparatively low maximum speeds in this speed range
should be adopted for relatively shorter transport distances. The
exact value of the maximum speed in this speed range ought to be
further determined based on the integrated performance of the
EMU’s passenger capacity, engines, streamline body design, and so
on. If the transport distance is longer than 1,800 m, the generalized
expense of energy and time per 10,000 passenger-kilometers
decreases with the increase of the maximum speed of the metro
EMU. Nevertheless, such decreases become very slow when the
maximum speed of the EMU exceeds 70 km/h.
6582
X. Feng et al. / Energy 36 (2011) 6577e6582
6. Conclusions
As for a certain utilization ratio of the total area in the cars of
a metro EMU, the TEC per unit transport of a metro EMU increases
with its maximum speed’s improvement, whereas the TOT per unit
transport decreases with the increase of the EMU’s maximum
speed. When the maximum speed of the EMU is below some
certain value, the TEC per unit transport increases slowly and in
contrast the TOT per unit transport decreases very fast with the
improvement of the maximum speed. Moreover, transport distance
between stops is an essential factor for the EMU’s both TEC and TOT
per unit transport. While the EMU transports passengers with
a relatively high target speed, more energy and time are consumed
by unit passenger transport for a comparatively short stop-spacing.
If the EMU provides a comparatively slow transport service, such
influence of transport distance between stops almost disappears.
Furthermore, the EMU’s integrated design performs an important
effect on its unit passenger transport energy and time
consumptions.
According to the TOC per unit transport for both energy saving
and transport efficiency improvement in consideration of the
influence from various factors, it is empirically confirmed that if
a metro EMU provides transport services for distances between
stops shorter than 1,800 m, it had better take a maximum speed
higher than 30 km/h and meanwhile lower than 70 km/h. Shorter
transport distances between stops prefer comparatively lower
maximum speeds in this speed range. The exact value of the
maximum speed in this speed range should be further decided
based on the integrated performance of the EMU’s passenger
capacity, engines, streamline body design, and so on. If the stopspacing is longer than 1,800 m, the maximum speed of the EMU
could be higher than 70 km/h to obtain an ulterior decrease of the
TOC per unit transport, but such a further decrease is very small.
As a result, for a metro line or its some parts consisting of
comparatively very short transport distances between stations,
a certain number of trains should not stop at some stations whose
passenger volumes are relatively small, to improve efficiencies of
passenger transport as well as energy utilization. In addition, the
EMUs running on a metro line or its some parts with responsibility for small tasks of comparatively short transports between
stops should not set high target speeds, especially in non-peak
hours.
In this study, the effect of a rail line’s condition such as gradients
of ramps, radians of bends, etc. on the cost of energy and time per
unit passenger transport has not been considered due to insufficient data supports, which should be improved in our future
research. Moreover, only the performances of two types of metro
EMUs are analyzed in this work, and transport operations with
applying more types of EMUs should be comparatively studied to
further validate the above-interpreted conclusions in this research.
Furthermore, other rational means to determine the top speed of
a HSR train from various comprehensive perspectives are also
worth to be explored in the future.
Acknowledgments
This study is financially supported by the programs of “EnergyEfficient Technology & Policies of Rail Transit Operations in China”
(G-1010-13493) commissioned by The Energy Foundation, USA,
“Evaluation to the Effect of High-Speed Railway on Integrated
Transport System’s Structure and Service in China” (2011JBM067)
commissioned by Beijing Jiaotong University, P.R. China, and
the National Natural Science Foundation Research (70971010)
commissioned by National Natural Science Foundation of China,
P.R. China.
References
[1] National Bureau of Statistics of China. China statistical yearbook 2010. Beijing:
China Statistics Press; 2010.
[2] Hay WW. Railroad engineering. Chichester: Wiley; 1982.
[3] Andrews HI. Railway traction: the principles of mechanical and electrical
railway traction (Studies in mechanical engineering, 5). New York: Elsevier;
1986.
[4] Martin P. Train performance and simulation. In: Farrington PA, Nembhard HB,
Sturrock DT, Evans GW, editors. 1999 Winter simulation Conference
Proceedings. Phoenix: IEEE (Institute of Electrical and Electronics Engineers);
1999. p. 1287e94.
[5] Magel E, Tajaddini A, Trosino M, Kalousek J. Traction, forces, wheel climb and
damage in high-speed railway operations. Wear 2008;265(9e10):1446e51.
[6] Ding Y, Zhou F, Bai Y, Li R, Mao B. Train grade resistance calculation modification model based on measured data. Journal of Transportation Systems
Engineering and Information Technology 2010;10(6):82e8.
[7] Kokotovic P, Singh G. Minimum-energy control of a traction motor. IEEE
Transactions on Automatic Control 1972;17(1):92e5.
[8] Uher RA, Sathi N, Sathi A. Traction energy cost reduction of the WMATA
metrorail system. IEEE Transactions on Industry Applications 1984;20(3):
472e83.
[9] Hoyt EV, Levary RR. Assessing the effects of several variables on freight train
fuel consumption and performance using a train performance simulator.
Transportation Research Part A: General 1990;24(2):99e112.
[10] Liu R, Golovitcher IM. Energy-efficient operation of rail vehicles. Transportation Research Part A: Policy and Practice 2003;37(10):917e32.
[11] Huang Y, Qian Q. Research on improving quality of electricity energy in train’s
traction. Control and Decision 2010;25(10):1575e9.
[12] Chui A, Li KK, Lau PK. Traction energy management in KCR. IEE Conference
Publication 1993;1(388):202e8.
[13] Lukaszewicz P. Energy consumption and running time for trains: Modelling of
running resistance and driver behavior based on full scale testing (Doctoral
dissertation). Stockholm: Royal Institute of Technology; 2001.
[14] Miller AR, Peters J, Smith BE, Velev OA. Analysis of fuel cell hybrid locomotives. Journal of Power Sources 2006;157(2):855e61.
[15] Bocharnikov YV, Hillmansen S, Tobias AM, Goodman CJ, Roberts C. Optimal
driving strategy for traction energy saving on DC suburban railways. IET
Electric Power Applications 2007;1(5):675e82.
[16] López I, Rodríguez J, Burón JM, García A. A methodology for evaluating
environmental impacts of railway freight transportation policies. Energy
Policy 2009;37(12):5393e8.
[17] Schafer A, Victor DG. Global passenger travel: implications for carbon dioxide
emissions. Energy 1999;24(8):657e79.
[18] Wong WG, Han BM, Ferreira L, Zhu XN, Sun QX. Evaluation of management
strategies for the operation of high-speed railways in China. Transportation
Research Part A: Policy and Practice 2002;36(3):277e89.
[19] Liu H, Mao B, Ding Y, Jia W, Lai S. Train energy-saving scheme with evaluation
in urban mass transit systems. Journal of Transportation Systems Engineering
and Information Technology 2007;7(5):68e73.
[20] Hsu C, Lee Y, Liao C. Competition between high-speed and conventional rail
systems: a game theoretical approach. Expert Systems with Applications
2010;37(4):3162e70.
[21] Chandra C, Aqarwal MM. Railway engineering. New York: Oxford Higher
Education; 2008.
[22] Mao B, Li X, Niu H. Train performance calculation and design. Beijing: China
Communication Press; 2008.
[23] EC (European Communities). Transport research fourth framework programme strategic research: DG-VII 99: Meet methodology for calculating
transport emissions and energy consumption. Luxembourg: Office for Official
Publications of the European Communities; 1999.
[24] IFEU (Institut für Energieund Umweltforschung Heidelberg GmbH). Energy
savings by light-weighting (final report). Heidelberg: the International
Aluminium Institute (IAI); 2003, http://www.world-aluminium.org/cache/
fl0000125.pdf.
[25] Ding C, Mori K. Discussion on energy saving operational speed of metro train.
Railway Locomotive & Car 2009;29(3):48e50.
[26] van Wee B, van den Brink R, Nijland H. Environmental impacts of high-speed
rail links in cost-benefit analyses: a case study of the Dutch Zuider Zee line.
transportation research Part D. Transport and Environment 2003;8(4):
299e314.
[27] Lindgreen E, Sorenson SC. Simulation of energy consumption and emissions from
rail traffic evaluation, report No: MEK-ET-2005-04. Lyngby: Technical University
of Denmark (Assessment and Reliability of transport Emission Models and
Inventory systems Project funded by the European Commission within the
5th Framework research Programme, Contract No. 1999-RD.10429). 2005,
http://www.inrets.fr/ur/lte/publi-autresactions/fichesresultats/ficheartemis/
non_road4/Artemis_del7a_rail.pdf.