Report 2 Why Light Rail Transit (LRT) was selected over Monorail Megapolis Transport Planning Team
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 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 expensive, then goes "at grade completely separated", then "at grade partially isolated", and finally in many cases the cheapest is "street running".
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).
What is Monorail? Modern monorails depend on a large solid beam as the vehicles' running surface. There are a number of competing designs divided into two broad classes, straddle-beam and suspended monorails. The most common type is the straddle-beam, in which the train straddles a steel or reinforced concrete beam 2 to 3 feet (0.61 to 0.91 m) wide. A rubber-tired carriage contacts the beam on the top and both sides for traction and to stabilize the vehicle.
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 Route Length Commencement Period* RTS1 Green Line Fort Kollupitiya-Bambalapitiya- Borella-Union Place- Maradana 15km Short Term RTS2 Yellow Line Fort-Maradana- Mattakkuliya/Peliyagoda 11.5km Medium Term RTS3 Red Line Dematagoda-Borella-Kirulapone- Havelock City- Bambalapitiya 10km Medium Term RTS4 Purple Line Borella Battramulla 10km Short Term RTS5 Pink Line Battaramulla Kottawa via Malabe 9.6km Medium Term RTS6 Olive Line Malabe Kaduwela 6km Medium Term RTS7 Ash Line Peliyagoda-Kelaniya- Kiribathgoda-Mahara-Kadawatha 13km Medium Term *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.
Figure 1: Line Route Map of Proposed RTS System
Figure 2: Proposed RTS Network in CBD
Figure 3: Proposed RTS Network in Suburbs
Justification Main cause for the selection of LRT (Light Rail Transit) preferably referred as Light Metro over Monorail was its popularity 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 at-grade or elevated will significantly truncate associated cost. It 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. The number of cities in the world where monorails actually perform a general, practical urban transit function can probably be counted on the fingers of one hand and even there, it's usually a single-purpose, point-to-point operation.
Comparison between Light Rail Transits (LRT) vs. Monorail 1. Reduced Cost When the cost is compared between LRT and Monorail, Due to the possible ground operations, as a System LRT can reduce the cost significantly. This is mainly because of the instalment of Depots/Yards and the stations on ground. Moreover, the ability of the tack going on ground at the possible locations for example, when the RTS Lines 5,6 & 7 running from Battaramulla to Malabe and Kottawa, Paliyagoda to Kadawatha are considered, considerable portion can go on ground resulting in a drastic cost reduction while in the case of a Monorail, the whole network should be an elevated structure where the cost factor is high. 2. Switching Track switches are critical to the successful operation of any train based transit system and must be highly reliable. As it is shown in the below diagram, in a Monorail system switching needs to adjust a concrete beam. This will escalate the cost of construction where such complex switching process is not needed in a LRT System. l l
The types of switches associated with monorail is shown below. 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. 3. Expansion as a Network Monorail cannot be expanded as a network. The main reason for this is the crossings. Monorail can t have crossings whereas LRT can. In places like Borella as many lines are interconnecting, crossings are needed to ensure the interconnectivity and the continuity of the lines. 4. Providers and Establishment LRT systems are more established across the world as a passenger transport rail mode than of Monorail. In case of monorail, most of the time it s a single line running between two ends but not a network. But when the LRT is considered, in many contexts it has evolved as a network with different alignments within the same network for example a portion can be elevated and then in transforms to on ground at possible locations where this is not possible with Monorails. Moreover, providers are well spread across the world for LRT with variety of technologies and different kinds of rolling stocks fitting to different contexts are available than it s for Monorail. 5. Aesthetic Aspect Monorail is obviously slimmer than LRT. It s aesthetically more blissful than LRT. But traction system of LRT mainly have two categories as the Third rail system and the overhead catenary system. Third rail system will ensure the aesthetic vies of the urban context comparison to overhead catenary system.