The Present Traffic System

The transportation system of Dhaka is predominantly road based where non-motorized transportation (mainly rickshaw) has a substantial share. Dhaka Metropolis has heterogeneous traffic flows, as of 1996 an estimated 168,718 automobiles are on road. Rickshaws are the dominating mode of public transport. Around 80% of total trips in Dhaka City is comprised of non-motorized transport (NMT), only 5.9% trips are made by motorized transport (MT), and average trip lengths of NMT and MT are 18 and 27 minutes, respectively (Karim, et. al. 1998). Trips made by public transport especially buses are very low, only 0.9%. A substantial part of total traffic is non-motorized vehicles which enhance severe congestion especially in road intersections. Among the total trips about 43% are made using rickshaw and have been increasing continuously over the last 20 years. The cost of transport represents about 10.8% of total household incomes. 

In Dhaka Metropolitan Area, as of 1992 about 3094813 trips are made by public transport daily. Of them, about 1636898 trips are made with rickshaw, 251303 with auto-rickshaw, 69310 with auto-tempo, 2752 with existing rails, 284634 trips by water transport, and 693163 with the buses. The number of passengers in public transport has been increasing continuously over the last 20 years. However, there is a clear difference in the share of public transport trips to the city according to the corridor in question. The shares of public transport trips are higher from the south than from the north. The main reason to this is the socioeconomic status of the inhabitants of the areas. The people in northern part of Dhaka have higher income and higher car ownership than the people in southern part of Dhaka. 

The Problem

From the experience of other megacities, it can be said that road network alone can not satisfy the need for transportation of such a large city. However, the road network of Dhaka City is non-lane basis and all transport modes (motorized and non-motorized) use the same lane. Even at very small percentage of motorized vehicles (less than 5 motorized vehicle per 1000 people) the city dwellers are experiencing severe congestion everywhere in the city in all the working hours. There exist severe air and noise pollution caused by motor vehicles and a very high accident rate. Overcrowding, air and noise pollution, adequate nutrition, and other deficiencies in the physical environment frequently represent the most obvious manifestations of environmental health problems. However, there are less visible problems of the social environment, which should also be identified such as: differentials in mortality among urban residents from non-communicable diseases such as heart disease and cancer are related to social rather than the physical environment within the society. 

Besides being the capital of a highly populous country, Dhaka has a major role to play in the era of regional and sub-regional cooperation, which are being contemplated recently. However, the existing transportation system may become bottleneck for the development of the city. To maintain the economic viability of this City and to keep its environment sustainable, an efficient transportation system is imperative. 

Traditionally it was argued that transport exerted a strong positive influence on economic development and that increased production could be directly related to improved transport. Transport can release working capital from one area, which can be used more productively as fixed capital elsewhere (Button 1993). The inadequacy of transport facilities is one of the major bottlenecks to socioeconomic development of the major cities and a national integration. Often the lack of transport makes it difficult to introduce other social infrastructure such as education and medical service. Transport investment forms a major component of the capital formation of the developing countries and expenditure on transport is usually the largest single item in the national budget. Up to 40 per cent of public expenditure should be devoted to transport infrastructure investment with substantial supplements coming from outside international agencies such as the World Bank, UN, and other development aid agencies. 

To cope with the problems of increasing transportation demand, traffic congestion, deteriorating environmental quality, and inadequate traffic safety measures Light Rail Transit can be a probable solution. LRT is a modern and somewhat modified version of the traditional tramway. It has been introduced in some developing cities on the ground that it can offer a high capacity service with an appealing modern image, it is less expensive than full subway system, and it is environmentally friendly. Considering its potential, LRT may be proved a suitable solution to the present transportation need of Dhaka City. The government of Bangladesh is taking positive measures for commuter rail in Dhaka. It is now a matter of gearing up on an agenda to a sustainable transportation system for the next century. 

Dhaka's Traffic Pollution

In recent years, the frequency of environmental problems in Bangladesh and other countries has increased substantially, causing serious damage to lives and property. The most crucial questions that need to be addressed are: what really causes the havoc-creating environmental problems, the economic estimates of pollution effects on society, the possible solution of air pollution, and the social and infrastructure development to improve the quality of the city dwellers. 

In whole Bangladesh, the number of motor vehicles per 1000 people rose from 1.4 in 1982 to 2.28 in 1991, and 2.72 in 1995 (BBS, 1995). Nearly one third of motor vehicles are operated by diesel (truck, bus), which contribute a greater portion of urban SPM, SOx, and NOx, sometimes private cars are energized using a proportion of (3:2) gasoline and diesel. Pollution severity occur due to the high content of lead in gasoline, large number of high polluting vehicles, impure fuel, inefficient landuse, and overall poor traffic management (Karim et al, 1997). Major issues are the heterogeneous flows of traffic and two stroke engines moving in Dhaka's street which emit greater proportion of black smoke. Another dominating factor of Dhaka's traffic pollution is the number of auto-rickshaw and tempo. Their increase is most remarkable in Dhaka where the proportion of such two-stroke vehicles in the total vehicle population rose from 2.2% in 1982-83, to 18% in 1990-91 and as high as 23% in 1996-97 (Karim et al, 1997). It is not out of subject to mention here that the two-stroke engines (auto-rickshaw) moving in Dhaka City are simple modified forms of an Italian model of 1960's which emits 30 times more pollution than a normal car (Karim, 1997). 

Conclusion

It is quite difficult to imagine that basic transport services can be provided for a metropolis with 10 million people without reliable mass transit system. Changes in transport technology, have over time, exerted a strong influence upon the shapes and forms of the urban areas. It is, at the same time, true that although transport demand requires the development of rail mass transit system, financial restraints normally rejects the option and sometimes economic reason asks for better alternative solutions.