Why Light Rail Transit (LRT) was selected over Monorail

Report 2
Why Light Rail Transit (LRT) was selected over Monorail
Megapolis Transport Planning Team
Table of Contents
Executive Summary ........................................................................................................................ 2
Introduction ..................................................................................................................................... 7
Basic Concept ................................................................................................................................. 7
What is Light Rapid Transit (LRT)? ............................................................................................... 8
What is Monorail?........................................................................................................................... 9
RTS Proposed Network ................................................................................................................ 10
Comparison between Light Rail Transits (LRT) vs. Monorail ..................................................... 14
Discussion ..................................................................................................................................... 28
1
Executive Summary
The existing road and public transport service has virtually come to a standstill in the peak time
especially within the Colombo CBD area, the existing passenger demand is almost exceeding the
supply of transportation infrastructure. The average travel speeds is around 17km/h in the
western region and even lesser at 12km/h in the CMC area. While road expansions have been the
usual practice that has been adopted it has been proven that more expansion of roads will only
attract more and more private vehicles. Further, CBD does not have the luxury of available land
for expansion of the road the improvement of public transport has been long felt for decades
which has been addressed by the Megapolis Transport Plan which gives the highest priority to
public transport improvements. In line with the transport plan one of the public transport
improvements proposed is a new Rapid Transit System to be introduced in the CBD and
extended to the out of the CBD of Western Region where conventional railway cannot be
extended through highly urbanized areas. The best technology for a new Transit mode for the
selected urban context was investigated by an assigned group of expertise under Megapolis.
During the study, Light Rail Transit (LRT) and Monorail were considered elaborating its
capacity, slenderness of the structure and speed. This reports aims to justify the reasons behind
selection of LRT over Monorail as the suitable technology for the network considered in the
Western Region Megapolis.
2
The following table compares the features between LRT and Monorail.
Feature
LRT
Technology prevalence



Monorail
Well established in the world as a 
Relatively
passenger transport rail mode.
mostly operational in Japan.
388 LRT systems in the world1, 
Around 54 operating monorail
of which >200 are similar to that
systems in the world (of which
proposed by the Megapolis team.
10 are in Japan). 30 (56%) of
technology
them are within amusement
Primarily used as an urban transit
parks, airports and shopping
network solution.

new
60
new
systems
malls.
worldwide1.
urban
transit
systems).
under
construction. Over 200 planned
(not

Primarily used as a point to
point system.

Limited growth/adoption as a
preferred
technology
for
comprehensive urban solution.

Monorail has not been built in
Japan since 2003.
Technology/supplier lock 
Over 100 LRT manufacturers.
in
Widely used technology with
stronger

competition/supplier
base.
Cost
(monorail costs are based
on feasibility study done
by JAICA)

Limited
monorail
manufacturers
globally.
Limited
competition/supplier
base.
Overall System capital cost is 
Overall system cost is higher
considerably lower than monorail
than LRT.
with ground level operation. Up
to 12% reduction with 17%
ground level operation as in
Megapolis Plan.
1
http://www.uitp.org/sites/default/files/cck-focus-papers-files/UITP_Statistic_Brief_4p-Light%20rail-Web.pdf
3

The rough estimate for a LRT
system for the JAICA proposed
monorail
trace,
completely
elevated is approximately 4% (40
mill. USD) less with LRT system

Segments of track, particularly in
suburbs can be on ground saving

Constrained to be on elevated
structure with higher costs.
around 20 mill. USD/km ( 13 kms
approx. 17% in Megapolis)

Depots/Yards can be on ground, 
Monorail Depots/Yards have
approximately 66% % less than
to be elevated which is approx.
elevated monorail depot. The net
11% of total cost.
savings on depots is 7% for LRT

Cost of elevated station is
Allows ground stations which is
approximately
approximately 50% less cost than
ground station.
elevated stations.



2
times
a
The monorail guideway is
The civil work for an elevated
more slender than LRT and is
guideway
than
approx. 30% less cost just for
monorail and approximately 30%
the guideway, but effective net
higher cost.
saving for monorail is around
is
heavier
8%.

Needs a special track switch to
change directions that is 15


Uses a conventional rail switch.
time higher than conventional
The net savings on total coast is
rail
4% for LRT
switches approx. 6% of total
switch.
The
cost
of
cost
Total estimated cost for 75 km of
Megapolis
network
is 
Total estimated cost for 75 km
approximately 3.5 billion USD ,
of
roughly 0.5 billion USD in
approximately 4.0 billion USD
Megapolis
network
is
savings.
4
Expansion as a network

Expansion as network is easier. 
Switching and crossings easily
accommodated with conventional

Rarely used as network.
Crossings are not possible
unless
railway switch.
inhibiting
grade
separated,
feasibility
as
a
network solution for Colombo.

Switching possible, but around
15 times expensive than a
conventional trail switch as it
involves movement of concrete
beam structure.

More space is required to
accommodate
a
monorail
switch.
Operational
& 
Maintenance Cost

Common maintenance/back end 
Unlikely to serve as network
can be developed for entire
solution
network with single technology.
Therefore common back-end
long
term.
not possible.
Comparatively less compared to
monorail.
in

Higher than LRT with fully
elevated system operation of
stations and yards together
with higher cost of operations
for switching.

Requires
replacement
of
rubber tires at approximately
every 160,000km which is an
additional cost.
Alignment

Can go Elevated, at ground or 
Elevated only.
even underground.
Aesthetic/Other Aspect

Third Rail Technology allows 
Aesthetically more pleasing
operations
due to its slender structure and
without
overhead
5
Catenary

(wires)
therefore
more
light
penetration.
relatively aesthetically pleasing as
However, practical problems
monorail structure.
have resulted in walkways in
between the beams allowing
The
column
to
support
the
only limited light penetration.
structure is similar to monorail
but require a concreate deck 
Straddle-type
which
particularly vulnerable to the
can
penetration
have
less
light
monorails are
danger of "system droppings"
– hardware, water, lubricants,
or other materials falling from
the trains or guideway onto
pedestrians or motor vehicles
below.
6
Introduction
Within Colombo CBD area, the existing passenger demand in almost all the roads and in the
existing public bus transport service has been surpassed. Therefore, the traffic congestion is at its
peak, where average travel speeds have come down to around 10-15 km/h in city roads. A new
Rapid Transit System will be introduced in the CBD of Western Region. It will introduce new
transit modes and will provide easy access to the major attractions in the system. It will ensure a
higher quality service for everyone in terms of cost, time and safety introducing a new mode will
help the rider to choose most appropriate mode of transport based on his trip purpose and hence
will increase the modal shift towards the public transportation reducing the traffic congestion
significantly. All the major points in the CBD will be connected by the new system.
Faced with the escalating demand for public transportation in metropolitan areas, transportation
authorities are challenged to select a technology that will satisfy the often conflicting demands of
high capacity and reliable service, urban fit, minimized environmental impact and budget
restrictions.
Basic Concept
The Western Region Megapolis Transport Master Plan is focus on improving the public transport
modes, not only to address the loss of public transport share observed over the past which is
currently standing at 52%, but also increase the share up to 60%. The focus is to improve the
urban railway so that major share of passengers can be carried by railway in line with the
practices of urban systems all around the world. However, urban railway is unable to be
extended to some corridors and also with the central Business Districts (CBD) considering the
inability of a surface railway going across highly built up areas such as Battaramulla. Further the
land prices and land scarcity within the central Business Districts (CBD), a need for a rapid
transit system that could provide a fast, reliable and comfortable ride to the passengers who are
brought to the city through urban rail is required.
Generally, there are three possible types of alignment for a rapid transit system: underground, at
grade, or elevated structure. "At grade" can be completely isolated, can be partially isolated (with
grade crossings), and can be mixed with traffic (street running). In terms of the cost, the
underground alignment is typically the most expensive, the elevated structure is the second most
7
expensive, followed by "at grade completely separated", then "at grade partially isolated", and
the lowest cost is "street running".
It was identified that a, bus based system along within CBD is unable to provide a fast reliable
service and thereby unable to attract the current passengers in private modes to the public modes.
This requires a completely elevated system within the CBD. When considering the cost of an
elevated system, the infrastructure has to be maximized that the technology which provides the
highest possible capacity to be provided. However, it was found that considerable portion of
trace could go along the surface when extended to suburbs. The decision of rapid transit systems
was therefore streamlined to a decision between the two technologies of Light Rail Transit
(LRT) and Monorail.
What is Light Rapid Transit (LRT)?
"A lightweight metropolitan electric railway system characterized by its ability to operate single
cars or short trains along exclusive right of way at street level or elevated. These vehicles are
usually powered by overhead electric wires or third rail, and offer a frequent, fast, reliable,
comfortable and high quality service that is environmentally sustainable."
LRT is often identified by its right-of-way and vehicle weight and size. When compared with a
regional railway or metro, the system is lighter in terms of actual system weight. The terms
‘heavy’ or ‘light’ do not solely refer to weight, but also to the flexibility of a system to deal with
different types of right-of-way and to the ability to be integrated into a variety or urban
streetscapes (Topp, 1999). LRT is also designed to operate in a variety of environments. These
can include, but are not limited to, on-street, highway medians, railroad right-of-way (operating
or abandoned), pedestrian malls, underground or aerial structures and even in the beds of unused
canals. This characteristic is one that clearly distinguishes LRT from other types of rail modes.
The design flexibility makes LRT one of the most readily adaptable, permanent systems and
thus, is often less costly to build and operate than other fixed-railway nodes (Boorse, 2000).
8
What is Monorail?
Monorail can be described as a transportation mode which the vehicles are guided and supported
by a single rail or beam (Kikuchi & Onaka, 1998)2. Modern monorails depend on a large solid
beam as the vehicles' running surface. There are two main types of monorail systems;
1. Suspended – A system that a vehicle hand from the support beam, rather than ride atop it. Modern
systems based on the suspended system use concrete or steel beam and rubber tires cars.
2. Straddle beam – A system that a vehicle ride along the guiding support beam, which is made of
concrete or steel often referred as Alweg systems. These are the most common types of monorails
in operation which the train straddles a steel or reinforced concrete beam 2 to 3 feet (0.61 to
0.91 m) wide.
The systems is constrained to be supported by a columns therefore either runs on center island of
roadways or completely grade separated based on their design category. It is also suggested that monorail
vehicle and technology is not compatible with the mixed traffic operations due to the guideway beams.3
Kikuchi ad Onaka (1988) describes the monorail as being composed of vehicles, guideway, stations and
control systems. These components are common across rail based rapid systems, however the vehicle
systems and guideway used in monorails have a significant difference, where vehicles use a rubber tire
wheels to stabilize and propulsion along the beam, which varies considerably to the more traditional
rolling stock and simple steel rail used in conventional rail based transit systems.
2
Kikuchi S., & Onaka A. (1988) Monorail Development and Application in Japan. Journal of Advanced
Transportation.
3
Kennedy, R.R. (ND). Considering Monorail Rapid Transit for North American Citiea. Retrieved June 1 2016, from
http://www.monorails.org/webpix%2020/RyanRKennedy.pdf
9
RTS Proposed Network
A detailed and comprehensive study has been carried out to decide the RTS route network in
order to match on going and future developments proposed by Megapolis Plan. The route
formulation methodology is attached in the Transport Master Plan Report as Annex 01 (Refer
Annex 01 for conceptual details). Accordingly, below table summarize the basic details of the
identified 7 RTS Lines.
Network will be Elevated in CBD and Elevated/At ground on Suburbs (75Km) – Approx. 63km
Elevated, 12km At ground.
Name
RTS1
Route
Green
Fort–Kollupitiya-Bambalapitiya-
Line
Borella-Union Place- Maradana
Yellow
Fort-Maradana-
Line
Mattakkuliya/Peliyagoda
Length
Commencement
Period*
15km
Short Term
11.5km
Medium Term
10km
Medium Term
Borella –Battramulla
10km
Short Term
RTS5 Pink Line
Battaramulla – Kottawa via Malabe
9.6km
Medium Term
RTS6 Olive Line
Malabe–Kaduwela
6km
Medium Term
13km
Medium Term
RTS2
RTS3 Red Line
RTS4
Purple
Line
RTS7 Ash Line
Dematagoda-Borella-KirulaponeHavelock City- Bambalapitiya
Peliyagoda-Kelaniya-KiribathgodaMahara-Kadawatha
*Immediately – Within 6 months, Short Term – 6 months to 3 years, Medium Term – 3-5
years, Long Term – more than 5 years
Following Diagram depicts the conceptual plan of the proposed RTS System comprised with
7 different lines.
10
Figure 4: Line Route Map of Proposed RTS System
11
Figure 5: Proposed RTS Network in CBD
12
Figure 6: Proposed RTS Network in Suburbs
13
Comparison between Light Rail Transits (LRT) vs. Monorail
1. Technology Prevalence
LRT is an extension or an evolution of tramway technology. While tramways were running in a
large number of cities in the then developed world in the 1920s and 1930s, many systems were
scrapped in the post-World War II period. Since the early 1980s there has been a revival with
LRT systems opened in 42 cities between 1985 and 2000 and in another 78 since 2000.
Currently, Light Rail Transit (LRT) and tramway systems are in operation in 388 cities including
Portland, Houston, Ottawa, Toronto, Dublin, Barcelona, Frankfurt, Bordeaux, Nice, London,
Melbourne and Sydney. Majority of the LRT systems are in Europe (206) and Eurasia (93)
followed by Asia (41) and North America (36). Germany and Russia alone feature 123 systems
(31% of total).
There are 2,300 lines for a total of 15,600 km of track carrying around 13.6 billion passengers
every year (45 million daily). Regions like the Middle East & North Africa (MENA) and Asia
are developing new infrastructure at a fast pace, while Africa and South America are starting to
consider LRT as suitable solution. In parallel to the increase in the number of systems, many
cities have invested to expand their network. The 15,618 km of track infrastructure and around
32,245 stations/stops translates into an average distance between stops of 484 m. The longest
systems are found in Melbourne (245 km), Saint Petersburg (240 km), Cologne (193 km), Berlin
(192 km) and Katowice (183 km).
According to the International Association of Public Transport, 850 km of track infrastructure
are under construction (60 LRT networks) and 2,350km (200 LRT networks) providing evidence
as (1) the popularity of the mode and (2) the acceptance of the technology.
14
Source: UITP, 2015
Figure 1: LRT Statistics
Source: UITP, 2015
Figure 2: LRT Systems in Operation
15
Monorail is a relatively new technology which has around 54 systems in the world [Asia (14),
Africa (2), Oceania (2), Europe (13), Japan (10), North America (10), and South America (3)] in
contrast to the 383 LRT systems (14%). Majority of them (10) are operational in Japan. The
remaining systems are exist in Malaysia, Europe, Russia, Korea, China, Brazil, UAE, Saudi
Arabia, Singapore and a few in the United States.
The monorails are primarily used for internal circulation such as theme parks, between airport
terminal and shopping malls. This is evident with 30 of the total 54 of the current systems (56%)
falling in to this category. When it is not used for internal circulation it is primarily used as point
to point connectors in an urban transport environment and has not evolved as a network to
provide an urban solution, which is discussed in latter section.
Japan plays major role in promoting monorail with 10 (18%) of the world systems being within
the country with 7 of them being urban transit systems. Surprisingly, no new monorails have
developed in Japan for the last 13 years, with the last monorail system being opened in Okinawa
in 2003 showing limited growth/adoption as a preferred technology for comprehensive urban
solution. Monorails are also less researched than other modes while conventional rail systems
have a wealth of literature to draw upon. The following table summarizes the Monorails under
operation in Japan where the longest operational monorail system is in Osaka with 28 kms.
Table 1: Monorail Systems in Japan
NAME
LENGTH (km)
NO.OF STATIONS
JAPAN
Ueno Zoo
3
2
Tokyo
17.8
11
Shonan
6.6
8
2
2
Kitakyushu
8.8
13
Chiba city
15.5
18
Osaka
28
18
Tama
16
19
Disneyland
4.8
4
Okinawa
12.8
15
Higashiyama
Average Length
11.53 km
16
Figure 3: Monorail Statistics
Any new technology bound to have technical glitches while it evolve and it is quite evident with
number of technical glitches on Mumbai monorail system that left the passengers stranded in an
elevated train for hours not once but several instances. Further, Mumbai monorail has been
having issues with the availability of spare parts that has resulted in several breakdown of
service. Apart from the case of Mumbai, several other incidents of failed and isolated Monorails
have been reported from around the world. Termination of Monorail in Sydney, Kuala Lumpur
Monorail being bailed out, Jakarta shifting the Monorail project to a LRT project in the middle
of construction and the Malacca Monorail been on idle due to technical problems can be listed
down as few questioning the suitability of the technology
The technology prevalence is clearly with LRT in terms of current operational systems in the
world and the numbers either in construction or in planning stage. The LRT clearly stands out as
an evolved technology and enough research to support the technology.
17
2.
System Cost
The system cost of both LRT and monorail composed of vehicles, guideway, stations and control
systems. Most of the literature states that the cost component of both LRT and monorail remains the same
when considering an alignment on elevated section with 50 million USD/km. However, with LRT having
the luxury of operating on ground the cost can be considerably reduced to around 30 million USD/km.
The above figures are rule of thumb figures while detailed constructed cost shown for monorail in Table
2 and for LRT in Table 3 shows that the final cost depends largely on the system, alignment which will
be unique for each scenario. However what is noteworthy is that monorail cost is rather contrastingly
different in Asia and North America which can be attributed to the lower cost of labour in Asia.
Following Table depicts the cost associated with some prominent Monorail systems all around the world.
Table 2: Cost of Monorails around the world
Project
Chiba (Japan): Monorail (extension)
Cost/Mile Cost/km (2002)
(2002)
Mill. USD/km
Cost/km (2016)
Mill. USD/km
128.2
80.125
$105.61
81.1
50.6875
$66.81
205.9
128.6875
$169.61
Kuala Lumpur (Malaysia) (new)
58.2
36.375
$47.94
Las Vegas (LVMC Project, new)
166.7
104.1875
$137.32
Newark: Monorail AGT (new)
223.1
139.4375
$183.78
Okinawa (Japan): Monorail (new)
103.9
64.9375
$85.59
Average
138.2
86.375
$113.84
Jacksonville: Skyway (new)
Kitakyushu (Japan): Monorail (new)
[Sources: Capital Metro, Rapid Transit Project, ADraft B Milestone 2 Executive Summary: Urban Transit Vehicles@, 1 October
2001; Steve Arrington, Jacksonville Transportation Authority, 12 October 2001; Leroy Demery, Jr., May 2002; Monorail Malaysia,
news release, 23 April 2001; Jacob Snow, AThe Las Vegas Monorail@, Monorail Society website, 2002/11/02. Calculations by
LRP]
18
Following two tables shows the cost associated with surface LRT systems and LRT systems with
extensive civil works around the world.
Table 3: Cost of LRT Systems Around the World
Surface LRT projects
Cost/Mile (2003) Cost/km (2003)
Project
Cost/km(2016)
Charlotte (new)
$31.10
$19.44
$25.05
Dallas: North Central (ext.)
$41.40
$25.88
$33.34
Dallas: NW/SE (ext.)
$51.10
$31.94
$41.15
Denver: West Corridor (ext.)
$56.80
$35.50
$45.75
Denver: Southeast corridor (ext.)
$46.00
$28.75
$37.05
Louisville: South corridor (new)
$44.70
$27.94
$36.00
Phoenix: East Valley (new)
$61.20
$38.25
$49.29
Portland: interstate Ave. (ext.)
$60.30
$37.69
$48.56
Salt Lake City: North-South (new)
$20.80
$13.00
$16.75
Salt Lake City: University (ext.)
$42.40
$26.50
$34.15
Salt Lake City: Medical (ext.)
$59.60
$37.25
$48.00
San Diego: Mid-Coast (ext.)
$38.70
$24.19
$31.17
AVERAGE
$46.20
$28.88
$37.21
LRT projects with Extensive Civil Works ( Tunnels, Elevated, subways, viaducts)
Project
Cost/Mile (2003) Cost/km (2003)
Cost/km(2016)
Dallas: DART S & W Oak Cliff
$33.2
$20.75
$26.74
Dallas: DART - North to Park Ln
$62.2
$38.90
$50.12
Los Angeles: MTA Blue Line
$46.1
$28.81
$37.12
Los Angeles: MTA Green Line
$52.1
$32.56
$41.96
Portland: MAX Westside line
$60.2
$37.62
$48.48
St. Louis: Metrolink (new start)
$37.2
$23.25
$29.96
$48.5
$30.31
$39.06
Average
The total system construction cost can be divided in to, E&M Systems, Rolling Stock, Civil
Works, Station Construction, Depot Construction, Track Switches and Maintenance. It could be
assumed that the E&M systems and Rolling stock remain very similar between monorail and
19
LRT. Following are a comparison of costs that can vary between the two technologies. It should
be noted that some of the values are rough estimates.
Alignment
There is no conclusive research is available to compare the costs between monorail and LRT
construction costs. What is available is costs for each of the systems. The effort here is made to
compare the costs of the JAICA proposed monorail trace with t a potential LRT line in a more at
an aggregate level. The RTS traces for the Megapolis has major portion as elevated since it is
proposed within the CBD and heavily urbanized areas. However, the portion that can go on
ground accounts for 13kms out of proposed 75kms which is 17% of the total length. Due to the
possible ground operations, the total system cost can be reduced significantly. This is mainly
because of the instalment of Depots/Yards and some of the stations on ground. An elevated
depots have a huge costs associated which needs elevated structures to park the vehicles. The
monorail feasibility done by the JAICA for a 23.1 km of track length has proposed a 5.3 kms of
track within the depots showing the extra cost that will be required for such facilities. The typical
ground depot is 50% less than an elevated depot, while it is similar for stations as well.
Civil Work for tracks
Civil work consists of construction of track girders and substructures for the tracks. A monorail
elevated structure is more slender structure than a structure required for a LRT. A comparison is
given by Hitachi is shown below.
20
Hitachi suggests that the monorail cost is lower than LRT based on the 30% reduction in cost for
just the structure for the tracks. However, it is sometimes misleading since the numbers cannot
be verified. Based on the cost estimates for the JAICA proposed monorail for Colombo of 23
kms, the total cost for structures is 27% of the total cost of 131 billion JPY in 2014 values
(bridge for switch is for track switches). Therefore the net savings to the total system due to
slender structure of a monorail will be 8% of the total cost.
Parsons and Brinckerhof4 report on Advanced LRT and Monorail Comparison in 2002 states that
monorail advocates often argue that the y simpler beam guideways (beamways) for monorails
may, on average, cost less than the support deck and trackage for an elevated dual-steel-rail
system (which requires the addition of rail structure above the beamways). However, the cost
advantage is probably offset by other limitations such as monorail switches appear to entail more
complicated machinery, and have a significantly higher cost – about 15 times the cost of an
ordinary railway switch.
Track Switch Costs
The track switch cost component even though smaller in number has a great impact on the total
system cost as monorail switch is 15 times higher than an ordinary switch. The cost becomes
significant with the increase of track length.
Based on the JAICA study the 23 track switches are proposed for a 23.2 kms of main tracks. The
total costs of track switches (5 bill. JPY) and the bridge for switches (36 bridges) accounts for
6.7 billion JPY in 2014 values (5% of total cost). This is roughly 66 million USD which comes
to 2.9 million USD/km just for switches. The total costs for LRT switch would be a total of 4.4
million USD (87% reduction) for all the switches based on PB estimates. Based on the JAICA
study it will be a net savings of 4.3% of the total costs for LRT.
4
Parsons Brinckerhof Quade & Douglas, Inc., Advanced LRT and Monorail System Comparison, July 2002
21
The detailed switch costs based on JAICA study is shown below. The cost of depot switches will
be considered as a cost for depot.
Depot/Yard Costs
By far the greatest cost liability of monorail to its greatest inflexibility, the need to build grade
separated in some fashion. Therefore the depot and the yard itself for monorail have to be
elevated incurring considerable costs which will not be required for LRT as the yards, depots and
building can be all at grade level.
JAICA study shows that a train depot accounts for 11% of the total cost as shown below.
22
The cost component such as track switches which is 17% of the depot cost is saved with a LRT
depot. Further, the civil work which is almost 50% of the total depot cost is not required as the
tracks are laid on ground. Both of these components itself is around 66% cost reduction for a
LRT depot compared to a monorail depot. Based on JAICA study it turns out as a net saving of
over 7% for LRT.
Station Cost
The station cost will remain the same for both systems if the trace is entirely elevated. However
with 17% of the total 75km on Megapolsi network being on ground the stations can also be on
ground. The estimated number of station in the network is 49 elevated and 9 at ground (16%). It
could be estimated that a ground level station is approximately 50% less cost. The station cost is
approximately 21% of the total cost based on JAICA study and therefore considering the total
cost of network a 2% net savings can be expected from having 16% ground stations.
Overall System cost
Considering all elements of cost for LRT and monorail, it can be concluded that the system cost
is very similar between the two if the entire alignment is elevated. Even then there is a cost of
LRT seems to be around 4% less than monorail. The difference in cost between LRT and
monorail with increase ground level operation as shown in graph below which shows that with
17% ground operation as in Megapolis LRT proposal a cost difference can be 12% less with
LRT. The advantage is from the less cost for track with ground level operation saving roughly 20
million USD /km and also
with less cost with ground
level stations.
The
estimated
Megapolis
cost
network
of
with
LRT is 3.5 billion USD
while it is estimated that 4.0
billion USD will incurred if
a
monorail
system
is
considered.
23
3.
Switching
Track switches are critical to the successful operation of any train based transit system and must
be highly reliable. While LRT requires a simple rail road switch as shown in Figure 4, monorail
requires a complicated switching system such as shown in Figure 5. Vuchic (2007) finds the
switching issue on monorail as a one of the main limitations5. Other than the extremely higher
costs ranging to 15 times of a regular rail switch, he suggest that large areas are required
compared to a regular rail switch, which shows that the urban foot print advantage for monorails
is not constant for all systems. He further reason out that the switching issues are the reasons
monorails operate as single lines and that it is very complex to plan for network of monorails.
Figure 4: Typical Rail Switch
It also creates an operational concern as it is essential a segments of concrete beams that are
mechanically moved in to place, which takes 15-25 seconds in contrasts to 0.6 second switch
time for conventional rail. This will escalate the cost of construction where such complex
switching process is not needed in a LRT System and also implications on day to day operations
due to headway implications.
l
5
l
Vuchic V.R. (2007). Urban Transit Systems and Technology. Hoboken: John Wiley & Sons
24
Figure 5: Monorail switches
More the number of lines interconnecting more the switching will be complex and the associated
cost where as in our proposed system in the locations such as Fort, Maradana and Borella will
have more than 3 lines interconnecting.
4.
Expansion as a Network
Monorail has not expanded as a network. The main reason for this is the crossings. Monorail
can’t have crossings unless grade separated whereas LRT can.
The one of the few which is rare to find and probably the only location of a monorail crossing is
at NiuJiaoTuo Station in Chongqing Monorail in China which is ironically the longest monorail
at over 80 kms. Even then it is a grade separated massive structure as shown in figure above. In
places like Borella as many lines are interconnecting, crossings are needed to ensure the
interconnectivity and the continuity of the lines.
25
5.
Aesthetic/Other Aspect
Monorail structure is obviously slimmer than LRT.
It’s aesthetically more pleasing than LRT. The main
advantage monorail has over LRT is the aesthetics.
The day light penetration is obstructed by the deck of
a LRT structure while monorail structure allows
penetration as shown in figure below.
Monorail promoters habitually tend to portray
monorail systems as light, airy, slender, unobtrusive
structures sailing gracefully over fields and streets
typically only photos of renditions of single beam
guideways are presented. But the practical situation is
that the slender beam structure has result in various
operational issues such as evacuation of passengers
during breakdown since there is no platform for the
passengers to get off in case of evacuation. There have
been many instances where the passengers been stranded for hours such as in Mumbai where the
passengers had to be rescued with the help of fire brigade.
To
mitigate the practical issue, walkways between the monorail beams have been erected so that
26
people can walk out in such solution. But these in the end take out the only advantage of day
light penetration which is considerably blocked as in the picture on the right. The Las Vegas
project demonstrates, a bona fide, heavy-duty, real world monorail consists of a lot more heavy,
physical, elevated infrastructure than just a slender beamway.
Similar to monorails not requiring overhead power lines LRT has an advantage of using the third
rail system instead of the overhead catenary system. Third rail system will ensure the aesthetic
vies of the urban context comparison to overhead catenary system.
Further monorails are particularly vulnerable to the danger of "system droppings" – hardware,
water, lubricants, or other materials falling from the trains or guideway onto pedestrians or motor
vehicles below since monorail trains straddle their beam ways, with, typically, nothing
intervening between the beams and trains, and the ground below. Debris (including a tire) has
fallen on occasion from the Seattle monorail, and in August 2002, a pedestrian was hit and
seriously injured by a wheel falling from the newly constructed monorail in Kuala Lumpur
(Malaysia).
According to Patrick M (2014)
6
apart from the main switching issues monorail processes,
maintenance and energy use are worth considering. The literature shows that although monorail
vehicle along with LRT has a life span of around 30 years, monorail which has tires that run on
the beam only last 160,000 km requiring periodic replacement and additional operational and
maintenance costs. Further it is also suggested that energy consumption of monorail is 25-30%
greater than LRT technologies due to the rubber wheel system’s greater rolling resistance.
6
Patrick M et. al (2014), Monorails for Sustainable Transportation
27
Discussion
Main cause for the selection of LRT (Light Rail Transit) sometimes referred as “Light Metro”
over Monorail was the technology prevalence, where LRT is a well establish mode across the
world with around 383 systems operating and 60 been built and over 200 in the pipeline, which
is in contrast to 54 systems with monorail where majority are within theme parks and airport
links questioning the suitability of the monorail technology for a urban transit solution.
Second popularity or LRT corresponding to its versatility. Light rail can run on all possible
types of alignment (elevated, at-grade, tunneled), depending on the particular situation in a given
area of a given city, such as: cost, density, station spacing, ridership, etc. Moreover, the same
line can be running on one type of alignment in one area of the city and on another type of
alignment in another area of the same city depending on the possibility. Since the proposed
Rapid Transit system spreads through suburbs such as Battaramulla, Kottawa, Malabe, Kaduwela
and Kadawatha, considerable portion can be accommodated at-ground level while blended
facilities such as deports and stations can be located at ground level irrespective to line been atgrade or elevated will significantly truncate associated cost.
It was found that the cost of LRT is still lower even when complete elevated system is
considered even though marginal. However the cost difference gap tends increase with the
increased length of the system and the increase of ground operation of the system. It also incurs
lower operations costs as unlike for instance LRT does not pose switching issues. Although
monorail is unable to expand as a network with crossings LRT could be expanded. Plus there are
more providers across the world so we could have the system at a very competitive rate with the
best technology. The modern LRT system technology permits slender contemporary structural
supports ensuring the aesthetic beauty of the urban context. LRT technology proliferated
everywhere in the world beginning in the late nineteenth century to the present day, while
monorail systems remain few and far between, says a great deal about the relative versatility,
suitability, reliability, and cost-effectiveness.
Jakarta is a prime example of planners realizing that monorail is not suitable even after
construction has commenced and later changed to LRT. The planned monorail project in Jakarta
commenced construction in 2003 and was stopped in 2004 due to funding issues and later
recommenced in 2013 to once again stopped in 2015. The Jakarta monorail has gained criticism,
as it only connects shopping malls in Jakarta's city center, and would not connect to Jakarta
28
suburban that desperately need transportation infrastructure; thus was not be useful for Jakartan
commuters. Transportation experts deemed that the city center monorail project would not
answer Jakarta's traffic problems, but would only serves as a novelty tourists' ride.
It has been stated that “the shift of choice from monorail to light rail transit (LRT) system in
Jakarta was based on several considerations; compared to monorail, LRT has higher passenger
capacity, simpler intersection and switching system, and cheaper maintenance cost. With
common track gauge of 1,067 mm (3 ft 6 in), would make LRT easier to integrate with existing
Commuter line and planned Jakarta MRT”7
Finally, it should be noted that, considering all the aspects of LRT and monorail for the network
proposed in the Megapolis, LRT emerge clearly as the best technology to proceed with.
7
http://www.revolvy.com/main/index.php?s=Jakarta%20Monorail
29