The New Nation - Internet Edition

Engr. Shafiqul Alam

Many have written about the nagging traffic congestion of Dhaka, some blame the traffic police for their miss-management, some suggest withdrawing the old vehicles and introducing more new vehicles, some highlight making foot-over bridges & most interesting thing is-some think that the foot-paths have to be wide. But from the transportation engineering point of view…removal of traffic congestion is impossible by the above-mentioned way.

Dhaka is one of the most densely populated mega cities in the world with the present population of over 12 million. The percentage of roads is far below the standard limit (only 7% instead of 30%). Whenever population exceeds one million a mass transit should be introduced as a thumb rule of transportation engineering to ease traffic movement and save valuable human working hours. Studies show that in a single lane in one direction in an hour buses can carry only 5000 passengers at an average speed of 10-15 km per hour. Monorail or sky train can carry 20,000 passengers. On the other hand underground metro rail can carry 60,000-70,000 passengers at an average speed of 60 kph.

With the introduction of more buses the environment of Dhaka would be more polluted and roads would be totally stagnant. In contrast to this metro rail is totally free from emission as it runs on electricity. This electricity would be produced independently from coal or gas.

In case of elevated expressway (EE) it is impossible to make complete network throughout the city as the city is already saturated. That's why EE for certain portion is not sensible…decision like that would make the same scenario like two fly-overs. Most of the buses don't use Mohakhali fly-over because they would not get the passengers there and cant go to the gulshan…just one directional movementtreversibly buses coming from banai cant go to shatrasta & so on. On the other hand for the fly-over road-space has been wasted due to the columns and other works like beautification. Normally EE is used for the highway buses to pass the city without using the roads. Toll way of Chittagong also remains empty.

Construction of foot over bridges is not a very good decision as well because foot over bridges of various location of Dhaka remain empty…people don't feel comfort to climb upward due to psychological stress rather they like to go downward first then to upward and gulistan & karwanbazar under pass is the example of that. Again construction of underpasses is not needed now because there would be free underpass at the metro station.

Some compares Dhaka with Bangkok and some with that of New York. Bangkok has sky train but that is not a complete network and the fare is very high (15-30 Baht, almost 30-60 taka). The same situation was happened in Australia for a segment of metro, people was not interested to use that, because metro should be for the people but people are not for metro…for that they modified the network. On the other hand American Government gives subsidy for metro because of their sound economy. Metro is profitable in Japan, China, India, France and so on. To speak the truth underground metro has a proven track record of 150 years and more than 177 cities are using this transport comfortably.

Considering the above facts India has introduced metro in Calcutta and Delhi, one in Bangalore is under construction. More over they are going beneath the ganga in Calcutta to make the network complete. If metro is not profitable or is not the best solution then why they are going to build another strip in Calcutta, even though they are the manufacturer of buses? Another point is to be noted that they have used Cut & Cover method and kept the metro fare just like bus fare.

Some thinks that in case of earth quake or flood there would be sabotage in the tunnel…but metro tunnel can withstand earth quake in the magnitude of 9.2 Richter scale, on the other hand the over ground structures can sustain only 6. Anything like SIDR would totally collapse monorail or sky train. There is no chance of the entrance of flood water in the tunnel…in this regard please check the under-passes and underground parking of Bashundara and so on. Other sabotages are also not possible due to the integrated security, auto initiated braking system, fire suppression system etc.

Future expansion has to be considered and that is only possible in the underground and we can make several networks (6 networks-up to 180 feet) beneath the ground, one after another. For monorail, sky train or EE we can never make lines one above another.

Since Dhaka is an over populated city…here rider ship is also high and metro would be able to cater more than 15-20 lacs passengers per day and by adjusting headway 60-70 lacs passengers can be carried.

Valuable human working hours are wasted every day and wastage of imported fuel due to jam is a huge loss. With the introduction of metro these losses would be totally minimized and the economic gain would be 6000-7000 crore taka per year.

Cut & Cover method can easily be applied for the tunnel construction and the total cost for Dhaka would be 7000 crore taka. 80% city dwellers would get a metro station within one Km or less walking distance and by adopting BOT (Build - operate - Transfer) the fare would be just like bus fare. People of all class would be able to use underground. In contrast to this TBM is 5-6 times expensive than that of Cut & Cover and it's a slow process. For TBM Government has to pay huge subsidy, hence this method is not feasible. Another point is to be noted that TBM is used for the deep layer and hard soil (rock like soil).

For EE people have to pay additional toll with fare which is not desirable…on the other hand in the proposal of mono rail (1998) the fare was approximated as 1, 1.5, 2 usD, which is absolutely not feasible for a country like ours. People always feel bored in using buses and women, children, handicapped people are not habituated to use buses, that's why they use rickshaws and removal of rickshaws is not a wise decision as well.

One of the most unwanted but usual scenario of Dhaka is: auto-rickshaw & cab drivers want to move as per their will or charge 10-20 taka or more from the meter reading, even though they are sitting idle, which is the violation of citizen's Rights.

Traffic police have nothing to do because at mohakhali some buses goes to shatrasta, some turns to farmgate, some make the U-turn, coming from farmgate or others go to banani or gulshan and some goes to shatrastatin such a haphazard situation traffic police will do what? Modernization of signaling will do nothing too. These steps were taken previously but the result is not very good, which is far from satisfaction.

Only 2% people of Dhaka own cars and with the improvement of economy these number would increase significantly, we cant restrict it…when metro would be in operation this class would use metro in the peak hour & during the off-peak they would use own transport.

For EE, sky-train & monorail, the aesthetic view of Dhaka would be destroyed…the city would be more dirty & shaded. The exhaust from BRT (for EE) would make an isolated shade due to the turbulence in the upper region. For sky/mono once again there would be chaotic situation…it can carry few passengers, that's why people would not be able to depend on it & sky/mono for some portion…bus for some portion is not sensible. To cope with heavy population, we have to introduce heavy metro (underground metro rail) of independent network, where all the city entry points are connected and the busiest areas are covered concentrating on the existing traffic flow pattern.

Considering the fare, sustainability, future expansion, economic gain, track record, and environmental impact---underground metro rail by Cut & Cover method is the only solution to mitigate traffic congestion of Dhaka, eventually that would make pollution free green Dhaka. In this regard one thing is true that-we may have to go beneath the first network for the 2nd network in near future to cater the huge number of population as the population growth is very high in Dhaka. Then we may use TBM for some portion. We need the balanced diet but not the rich food.