Underground or elevated- making a right choice for Pune metro

More than a year and half now, we- the citizens of Pune are witnessing a major chaos that is going on with the Pune metro rail project. Everyone including consultant for the project, political parties, PMC administration, state government and the various NGOs have had their fair share in creating this chaos. And who is the sufferer? We, the citizens of Pune.

I am sure most of you must be as clueless as me on the various issues like

·         Is Metro railway the right public transport solution for my city?

·         Whether metro railway will be built in tunnels (underground) or on viaducts (elevated) and which is better for my city?

·         What problems will I face during the construction of this metro railway?

·         What problems am I likely to face once the metro railway is in operation?

Adopting metro railway as a public transport solution for the city should not be done in isolation. The metro railway should be a part of integrated urban public transport plan for any city for it to be successful. Such a plan comprises of Bus system (BRT and busses operating on normal routes), trams and metro railway. Here I am assuming that such an integrated plan is ready for Pune and only after such a plan is developed, the decision of adopting metro railway for Pune is taken.  I call it as a “benefit of doubt”

Now that the metro railway project is decided for Pune, the next question that created further chaos and confusion was “Whether to have underground or elevated metro corridors for Pune?” With the recent events it seems the issue is more political than techno commercial. In June 2010, Delhi Metro in their DPR recommended 15 Km of elevated corridor between Vanaz and Ramwadi. However on political front Shiv Sena, NCP and few corporators from BJP favour underground routes, while few others in BJP and the Congress support an elevated corridor. When chief minister Prithviraj Chavan promised speedy implementation of elevated metro, their partner NCP suddenly changed its view and favoured underground metro route. Shiv Sena then moved a proposal before the Standing Committee demanding an underground metro. The BJP later demanded that the issue should be decided purely on the advice from technical consultant. And couple of days ago NCP took a complete U turn on their stand and announced that the metro will be elevated.

I am sure there will be couple of more U turns on this issue.

I wonder on what grounds these coprporators decide which technology should be adopted for metro railway construction. Are they equipped enough (or at all) to make such a decision? I am not an expert on urban public transport planning or on the metro railway planning. However with the exposure I got to the metro railway industry though my profession, I thought of finding out how the decision of adopting the underground or elevated metro is made in other parts of the world. I would like to share these findings with all of you. Please note that these findings are not mine. I have taken references and inputs from various experts, organizations and papers published and have tried to collate the views. I hope it will help you to get fair insight into how the choice between “underground or elevated” metro is made.

The major factors that will generally influence the decision of “Underground Vs Elevated”  would be                          

Initial Capital Cost: Metro railway is most often the largest investment the city will ever make. Often these investments are significant compared to the economies of the city. So this decision is strongly influenced by the initial capital cost. Typically the underground construction will be 2.5 to 3 times more expensive than the elevated. So for Pune metro the cost of elevated section of 15 km estimated to be 2593 Crores may go up to about 7800 crores if full underground corridor is adopted. But with the advancement of technology in tunnelling and with the better productivity of TBMs (Tunnel boring machines) and especially in the cities where land cost his very high, this difference is fast narrowing down. For the newly developing areas of the city having wide roads, elevated corridors can be the choice due to lower initial construction costs and easy and cheaper land availability.                                                                                                                       

Visual and Aesthetics : It is true that the elevated metro structures (vaiducts/stations) strongly affect the visual character of the city. Whether this impact is good or bad depends on architecture and the perception of the citizens. The underground corridors do not have this impact. The fotos below show how the city aesthetics changes with underground and elevated corridors.
 

Khan Market Metro Station- Underground

 


KarolBaugh metro station- Elevated.

 

  








                                                                                                                                                                
Ridership:  In the thickly populated, densely constructed city areas having narrow roads generally it is not feasible to construct a new elevated corridor as it needs to follow the existing road network and the space is simply not available. Underground corridors do not need to follow this existing road network and hence can have a positive impact on ridership of metro rail because of more direct journeys requiring less interchanges reducing the travel time significantly. The interchange between two elevated lines is much more difficult for the passenger than the interchange between two underground lines. A new metro project will not automatically guarantee the ridership. It needs to be “won”. For enticing the potential passengers who have other modes of transport available to use the metro system it needs to be reliable and must reduce the travel time significantly. The right choice of elevated/underground corridor is must to win this ridership. In India, the underground corridors are adopted in areas like Connaught Place in Delhi and at Majestic in Bangalore where there are interchanges of different metro lines and also the metro corridor alignment is passing through the thickly populated and dense city areas.

Impact on existing adjacent properties and the development potential: In the thickly populated and constructed city areas, the elevated corridors will have a major negative impact on the frontage/ view of the existing properties. The elevated stations may also encroach some private properties. Some elevated corridors in Mumbai, Delhi and Bangalore are so close to the residential properties that it may become impossible to stay there. This may result into the property value going down in such areas. Underground corridors do not pose this threat.

Impact during construction: There could be a major traffic disruption during the construction of elevated metro as it follows the road network mostly. And do we consider the loss as an additional cost arising from this disruption resulting into longer travel times? During the underground construction such impact is limited only at access shafts for machinery and at station entry construction sites.

Land acquisition issues:  The elevated corridors may face major delays and cost increase due to land acquisition issues (litigations and costs), physical relocation of some adjacent properties and residents and above all the political influence hampering speedy land acquisition and relocation. In our country this is a major threat. Mumbai Metro, Bangalore metro, all these projects have been delayed because of these issues. Underground corridors will have significantly less problems with this.

Vibration and noise: Vibration could be a major threat posed to residents, historical monuments and businesses in case of underground corridors. However advanced technologies like Mass Spring System at negligibly higher cost effectively mitigate this problem. Such systems are used all over the world. In India Delhi metro, Bangalore metro, Chennai Metro are using such solutions in their underground corridors. As far as noise is concerned elevated metro can emit a significant air borne noise due to rail wheel interaction. One needs to go for costly noise barriers to mitigate this problem. Underground metros are quietest when the proper track isolation methods are used.

Operating costs: The underground metro operation costs increase due to ventilation, lighting, station air-conditioning, escalator systems, fire safety systems and maintenance needs compared to elevated metro. Dr. E. Sreedharan of Delhi metro has quoted that the operation costs of underground metro are 50% higher than that of elevated metro. Also the passenger evacuation in case of emergency becomes a critical issue in case of underground metro.

You must have realised by now that making a choice between underground and elevated metro is not an easy A+B=C decision. It is a complex economic, urban planning, engineering and political decision. And it will vary from city to city depending on the specific conditions and needs.

So what is the right way forward for our city?

1.       For a city like Pune, a mix of underground and elevated metro would be the right choice. Many cities in the world have adopted this mix depending on their specific needs. The following table is an example.

City	% underground	% elevated
Delhi Metro (India)-Phase III	50	50
Bangalore Metro	25	75
Copenhagen Metro (Denmark)	42	58
Madrid Metro extension (Spain)	68	32
Washington DC metro (USA)	57	43
Singapore	30	70
Seoul metro (Korea)	80	20
Mexico City (Mexico)	25	75

2.        In the densely constructed city area the metro needs to be underground. If the elevated metro is built in the city area it will have major issues with construction as the roads are quite narrow. It will play havoc with traffic during construction. Once ready it will permanently decrease the road width. It will also put major hurdles in future expansion of road width, construction of flyovers etc. Also future expansion of the metro line would be extremely difficult with the elevated metro in the city area. Also issues with relocation of buildings, residents and land acquisition will delay the project significantly. In the city underground metro stations should be connected with the effective bus system. This will discourage people to use their vehicles to commute up to metro stations and will help increasing the ridership. The use of underground spaces for the commercial activity would also help in funding the project.

3.       The industrial, business areas outside the city limit such as Hinjewadi, Chakan, Talegaon, Nagar road, new airport at Rajguru Nagar, should be connected with the elevated metro corridors. Here the metro route can follow the existing highway. The elevated metro is a feasible and economical option on these corridors due to possibility of easy and cheaper land acquisition. Also there would be a potential for real estate development along the metro corridor which can be an opportunity for funding of these corridors.

4.       While considering the costs I am sure, the planners have considered the other costs associated with the metro rail project like maintenance, operations, security, land acquisition and rehabilitation along with the initial capital cost. However long term benefits like increased economic activity due to metro rail corridor and development potential are normally not considered. The decision should be based not only on initial capital cost but must be based on all short and long term costs as well as all short and long term benefits.

5.       Advice from technical consultants no doubt must be sought for the complex technical issues. However as the owner of the metro, PMC must decide how we want our metro to be as it would be probably the largest ever investment they would be making on any of the infrastructure project. They should take a firm stand on,

a.       How we want our city to look like after metro railway is constructed. Are we ok with the visual impacts the elevated corridors will have on the aesthetics of the city?

b.      How are we going to plan our metro corridors so that it will require minimum relocation of buildings/ residents and will have minimum land acquisition problems? This will avoid delays in time and cost overruns.

c.       What are we going to do about the problems and traffic disruptions that our citizens will be facing during construction

d.      Where would development of the city take place in the future and how metro should connect these locations to the city.

e.      How are we going to complement the metro railway corridors with effective bus system so that the need to use private vehicles will reduce and the patronage (ridership) of the overall public transport system will enhance.

f.        Ways of funding the metro railway project and how the potential development along the metro corridors and the use of commercial spaces in the underground spaces will help funding the project.

Just leaving these decision to consultants may be detrimental to the future of our city as the consultant’s scope is “metro railway project planning”. He is not the urban planner. It is PMC’s job to make metro as an integral part of Pune’s urban development plan and make it successful. It is PMC who has to find out solutions for Pune’s problems.

I hope our politicians go beyond a petty party politics, show strong political will and maturity and make an informed decision about underground/elevated corridors for the Pune metro railway project. This is the minimum they owe to the citizens of Pune.

- Sanjay Risbood
(Engineer by Profession. CEO- Getzner India, Advisor- GreenEarth)