Dhaka is known as the rickshaw capital of the world. Although rickshaws do create a major problem by clogging up the traffic in Dhaka's streets, they are not the only problem. Other cities that do not have rickshaws have also to experience severe traffic congestion due to the natural proliferation of vehicular traffic and this is the principal problem in Dhaka. The number of cars, buses and trucks on the road is increasing steadily in Dhaka at a much faster rate than one can imagine, with little or no construction of new roads. The traffic congestion is so bad that even ambulances carrying patients in critical condition needing immediate medical attention are held up. The flyovers that are being built now are only temporary solutions to buy time. In fact the flyovers may create future problems of durability of the concrete in the tropical monsoon climate of Bangladesh. A long-term solution is unquestionably to build a well-planned subway system.

The advantages of underground subways are too many to enumerate. This is why other major cities of Europe, North America and Asia discovered long ago that conquering underground space is the best way to overcome the challenge of mass transportation. Asian cites that have already built or are building subways are Tokyo, Hong Kong, Shanghai, Beijing, Singapore, Taipei, Kolkata, Bangkok and Delhi. China is reportedly considering building subways in 20 of its most crowded cities. Cairo has recently completed a 52-km subway system. A subway has a low life-cycle cost and its maintenance costs are relatively low since the structure is naturally protected by the ground from the onslaughts of climate. The long-term economic benefits are immeasurable. An underground subway will offer sustainable growth and socio-economic development and result in the transfer of technology. If built piously, it can last for centuries. In addition to rendering the transportation of large masses of people easy and rapid, it will bring tourists and investment dollars. The list could go on. An underground subway will cost an estimated $50-100 million per kilometer, depending upon the method of excavation and the severity of problems encountered during construction. Proper design, optimization of route maps and the method of construction will determine the final cost. When one considers the economic loss of more than $200 million a year due to Dhaka's traffic ills and the low life-cycle cost, this initial cost is not really overwhelming. Financing of a subway project can be done by government funding, BOT, or a combination of the two. Matching funds and the assumption of partial responsibilities of operation of the subway by the Government of Bangladesh will go a long way to induce more private financiers to undertake the mega-project. In addition, an underground subway creates no noise or pollution. The technology of tunnel-building is so well established and advanced that it needs no further elaboration and emphasis. Moreover, underground subways have stood the test of time since 1863 and are still being employed in major world cities.

Of course, to develop and implement a master plan indicating routes, political will and determination are needed first. A so-called Metro Plan was devised in as late as 1995, albeit with no implementation in sight. In 1999, when the author visited Dhaka and met government officials to emphasize the need for building a subway system there, he was told that a mono-rail system in the new areas of Dhaka near the airport was being actively considered. That plan now seems to have been dropped or postponed.

The Communications Minister stated at a BUET Seminar that there exist several proposals with different options for addressing the city's transportation problems but the government would select the latest technology-based and appropriate solution. He mentioned that every rapid transit option would be considered. He further expressed his government's determination to build a magnetic levitation (Maglev) train system from Dhaka to Laksam. This brings forth important questions in the realm of public transportation. Is Bangladesh ready for such a system? Is it possible to consider this system for Dhaka?

The Maglev technology was conceived in the early 1900s by Emile Bachelet as a magnetic suspension system using repulsive forces generated by alternating currents. However, a great amount of power was needed for the conductors, making the idea impractical. In the 1960s when superconducting magnets became available, Bachelet's idea was revived and the concept of superconducting magnetic levitation drew considerable attention. Recently China has broken ground for the first time with its newly installed Maglev system based on German technology. A 30-km Maglev line has been constructed connecting Shanghai Airport to the city of Shanghai at a cost of $1.2 billion, or $40 million per kilometer. Maglev trains float nearly friction-free slightly above their tracks called "guide ways" and can potentially reach a high speed of up to 400km or more. They are noise-free and need no fuel since they are propelled by electromagnetic force generated by electricity along the guideway. Maglev trains do, however, require constant supply of power. The guide way has winding cables on either side that create alternating magnetic fields which are regulated to control the train's speed.

Although the benefits of a Maglev train system sound attractive at first sight, there are some concerns as well. First, unlike the tunneling technology, this Maglev technology is at its infancy in terms of its application and hence its long-term performance remains to be seen. Second, the high speed of trains will create intense air currents and turbulence that will shake nearby structures. Third, the full effectiveness of magnets is questionable in a hot and humid country like Bangladesh, perhaps demanding a greater amount of power than would normally be required. Fourth, there could be potential negative environmental effect of the strong electro-magnetic fields on health. Fifth, although it is a no-fuel system, it demands an immense amount of power, which is in short supply in Bangladesh. There could also be other unforeseen problems that have not been identified since such technology has not been tested over a long period of time and on a large scale. Given the difficulties of long-term maintenance of such a high-tech system by a country like Bangladesh where the infrastructure for cutting-edge technologies has not yet developed and where needed economic reform is still a long way off, the timing of undertaking a Maglev train project needs serious consideration. The need for such a system has to be justified in terms of cost/benefit analysis. The cost of the special trains required for the Maglev system is going to be prohibitively expensive. Such a system may be acceptable in the foreseeable future, but right now such a new and sophisticated technology is likely to outpace the developments of the local civic infrastructure and hence will disturb the delicate balance between the transportation industry and the society's preparedness to accept rapid and drastic changes.

Maglev is essentially a surface system and is difficult to build and operate in populated areas. There is simply no room for this in older Dhaka which is synonymous with overcrowding. An overhead Maglev system will be prohibitively expensive and hence impractical since the cost of building bridges supporting the guide ways will be an additional premium to be paid together with its other consequences. However, it can be given consideration for the outlying areas such as Savar, Gazipur, Rajendrapur, Kaliganj, Sonargaon, to name a few, that are still open and available for accommodating Maglev trains and could be effective for commuters who live far from Dhaka. This will encourage people to move away from the city and reduce the congestion there. In fact, construction of new satellite townships away from Dhaka that will function as bedroom communities is a good idea provided the necessary infrastructure exists and the residents can commute to the business districts of Dhaka with ease. Since Maglev trains are pollution- and noise-free, they may provide the citizens, who live in the outskirts of Dhaka, with an economical and fast mode of commuting. However, the right of way for such a surface system must be accomplished before the density of population exceeds a critical level. In the old Dhaka regions such as Mohakhali, Kawran Bazar, Farm Gate, New Market, Motijheel, Sadarghat, Sutrapur, etc. an underground subway system is the inevitable option for mass transportation.

All these factors point to the conclusion that the Government of Bangladesh should seriously consider the problem of transportation with urgency and as a national priority. The notion of transportation planning must encompass the entire city and the outlying areas. It must include all aspects of a grand scheme keeping in mind the projected growth of the city 20 to 30 years down the road, so our future generations are not burdened with problems that we will create for them now. If Dhaka has to remain a livable city, this challenge must be faced squarely by the government and the people along with other problems of shortage of water and electricity, urban pollution, crime, etc. The sooner this is done, the better.

Dr. Mir M. Ali is Professor and Chairman, Structures Division, School of Architecture, University of Illinois at Urbana-Champaign, USA.