Keywords: Traffic congestion, BRT, STP

Transcription

1 Evaluation of the BRT project at Dhaka to reduce the environmental impacts focusing on CO 2 emission reduction. Begum Swapna, Yoshiro Higano University of Tsukuba Abstract: Dhaka, the capital city of Bangladesh, is one of the traffic congested cities in the world. The rapid rise in population along with increased and versatile land use patterns and increase in motor vehicle ownership along with non-motorized vehicles on streets are responsible for enormous traffic travel demand and traffic congestion in this city. The transport sector in Dhaka, which comprised of many different modes of travel - both motorized and non-motorized often using the same road space resulting in a high level of operational disorder, that significantly diminishes the efficiency and effectiveness of the existing transport uses. Moreover, this situation has resulted in deterioration in accessibility, level of service, safety, comfort and operational efficiency, causing increased costs, loss of time, air pollution and psychological strain, and posing a serious risk to the economic viability of the city and the sustainability of its environment. Again, due to rapid growth of population in Dhaka, the projected trip generation per day for the next 20 year period is million which is about 8 times higher than the current trip generation per day [STP]. Therefore, there is an urgent need to introduce a well-organized, properly scheduled mass transit system (BRT) minimizing the existing problems. Keywords: Traffic congestion, BRT, STP

2 1. Introduction Dhaka, the capital and largest city of Bangladesh, is a very densely populated city. It is the center of commercial, economic as well as development activities of the whole country. It has the highest rate of urbanization in Bangladesh. According to Strategic Transport Plan the population of the greater Dhaka area is estimated to be 19.2 million people (STP 2005), a number that is expected to be more than double by Only seven percent of the city's land is used for roads against 25% recommended for a good city planning (Rahman 2008). In addition, the city also lacks an organized, properly scheduled bus system or any type of mass rapid transport system. Although Dhaka s area is less than 1% of the country s total land area, it supports about 10% of the total population and 30% of the total urban population (Rahman 2008). During the last four decades Dhaka has recorded a phenomenal growth in terms of population and area which has a substantial effect on transportation system of Dhaka. The problem of traffic congestion and uncontrolled vehicle emission make life miserable causing threat to health and economic loss as well. It is evident that traffic and transportation conditions in Dhaka City have seriously been deteriorated and in many respects have already reached a crisis level. These are affecting the city's efficiency performance and are being considered as a major impediment for her economic growth and development, causing frustration among the residents and prompting popular demands to find urgent solutions. It is true that various types of studies, plans and programs have been introduced in Dhaka city to overcome the transportation problems. But unfortunately no attempts to solve the problems have been successful. So, now it is essential to find out alternative solutions and the solutions should be oriented towards Mass Rapid Transit (MRT) options. Without MRT, it is quite impossible to solve the transportation problems of a city with huge population. There are different types of MRT options and choices on transit options are very important because choices on public transit options are choices about a city's future. Bus Rapid Transit has been successful and very popular transit option in many developed and developing cities and is being increasingly utilized by many other cities. As Dhaka is also a developing city, the experiences of other developing cities of introducing BRT may be applied in Dhaka city. This was also reflected in the Strategic Transport Plan (STP 2005) where ten alternative strategies have been evaluated for improved transport system for Dhaka. In order to solve the transportation problem in the metropolitan area, Government is now implementing the BRT project from Gazipur to Airport, proposed in STP, 2005 as BRT line 3. This study is an attempt to find out the effectiveness of this project in the context of environmental pollution reduction as well as the economic evaluation of this project. 2. Existing modes of travel in Dhaka metropolitan city 2.1 Rickshaw Rickshaws are three wheeled cycles called cycle rickshaws. It is manually operated giving door to door services to the passengers. The rickshaws normal carrying capacity is

3 two passengers. Because of their size, rickshaws can easily operate on lanes and by-lanes of the city. Although it is slow moving vehicle, rickshaw journey is cheaper and comfortable. 2.2 Auto rickshaw The auto rickshaws are three wheeled mechanically operated vehicles, whose body is generally manufactured locally but the chassis along with the engine is imported from foreign countries. The auto rickshaws carrying capacity is three persons at the back and the driver in the front. 2.3 Auto tempo The auto tempo is like the auto rickshaw based on three wheeled scooter chassis, but instead of three seats behind, its seat arrangement is such that it can carry 10 persons at the back and two persons at the front, beside the driver. The auto tempo generally travels on specific routs. 2.4 Taxicab The taxicabs are like the passenger cars but are operated by a company or by an individual and available to all persons who meet the conditions of a contract for carriage (i.e. pay prescribed prices). 2.5 Large buses Large buses are defined according to regulation as buses with more than 32 seats, but more generally large buses are considered to be ten (10) meters or more in length. According to BRTA report, numbers of buses are registered upto Mini buses Mini buses are defined as buses with 15 to 30 seat capacity, excluding the driver. Most mini buses are around 8 meters in length, with locally manufactured bodies and Isuzu, Hino or Tata chassis and engines. 2.7 Human haulers/auto tempo Human haulers are 9 to 15 seated, generally in the form of a converted pickup truck with two benches added for passenger seating. Most have diesel engines, although some are petrol fueled and a small number have converted to CNG. 3. Percent modal split The latest surveys of person s movement in metropolitan Dhaka under the Dhaka Urban Transport Project showed walking as the predominant mode with a share of 62 percent of total person trips. This is followed by rickshaw (13.3%), bus (10.3%), auto rickshaw (5.8%), and car (4%). In consideration of person trips by vehicle, rickshaw takes the highest share, accounting for 35 percent followed by bus (21%), auto rickshaw (1.5%), and car (10.5%) (JBIC, 2000).

4 4. Deficiencies in existing mass transit system Current supply of mass transit is much lower than the actual demand. At present, only 31% of daily trips made by mass transit whereas this was only 22% in 1994 (DITS 1994). Not only the lack of this supply, there are also many other deficiencies in the existing system of mass transit. These deficiencies can be resulted from Road limitations as well as Operational difficulties. 4.1 Limited road space As in many other cities in the region, systematic bus route planning based on a cycle of monitoring, planning, and implementing adjustments to the network is not in place in Dhaka. The total road length of the DCC area is 1286 km whereas primary, secondary, connector, local and narrow roads are km, km, km, km, and km respectively. Total space occupied by roads and streets of Dhaka Metropolitan City is only 9% of its total space while that of other mega cities cover approximately 25%. Though 9% of road area of the city is available, pavement area is only 6% of total area (RMMS, 2004). 4.2 No road network pattern As road network of Dhaka City evolved haphazardly without any plan and always to meet short term travel need, the total road network does not show any well-defined configuration. Instead, it is expanded eccentrically in the north-south direction and allowing uncontrolled ribbon development. 4.3 Unorganized and non-integrated road network During last twenty to thirty years, significant road development has been taken place to cope with sudden transformation of the city from provincial town to the capital of a sovereign country. But most of the transport developments have been driven by ad hoc considerations having no explicit focus on analysis of existing demand or future requirements. As a result, the road network of the city is not organized and integrated in terms of connectivity. 4.4 Mixed operation in major roads Road network of Dhaka city is characterized by mix traffic system. All types of vehicles, both motorized and non-motorized vehicles are in operation on each and every road, except some NMT restricted routes. Because of the presence of non-motorized vehicles, travel speed is significantly reduced for motorized vehicles and a huge congestion occurred. 4.5 Low roadway capacity and speed Due to the complex mixture of motorized and non-motorized traffic and non-lane based movement over the Dhaka city road network, the capacity & speed of vehicles has abruptly decreased. The capacity of road lane and speed of the transport mode are very low compared to other capital cities in the world. That is how the city is facing huge traffic congestion at everywhere of the Dhaka city. 4.6 Absence of bus priority measures

5 Public transport is currently not given any priority over other vehicle types and road users. Various forms of bus priority ranging from traffic signal priority measures and bus lanes to possibly dedicated bus-ways should be considered for application in Dhaka. There is no bus only routes or segregated bus lane on roads. 4.7 Poor maintenance and surface conditions of road The surface conditions of most of the roads are very poor. The surface of the roads are not smooth, as a result, journey through vehicles on such roads is not comfortable. 4.8 Road space occupied other than traffic Most of the roads are not fully used by traffic. Presence of dustbin on roads is very common in Dhaka city. This significantly reduces the effective road width for traffic use. Road spaces are also occupied by hawkers and retailer traders. In many places, construction materials for building are placed on the road. These cause reduction in effective road width and make the road unsafe for vehicles. Again, on-street parking also reduces road spaces and hinders smooth flow of traffic. 4.9 Lack of bus lay There is very few designated place for bus stoppage in road side of Dhaka city. Most of the bus stop in road side haphazardly with competition attitude and alighting and boarding passenger dangerously. This makes always crowed on road side and influence pedestrian to move on road as well as decreases the effective width of the carriage way Less productive intersection: Intersection capacity is always reduced by the frequent stopping or public transit vehicles, especially buses, tempos and rickshaws, inside the intersection. Again there is no practice of clearways in Dhaka that severely inhibits the performance of intersections Absence of automated and integrated traffic signals: There are about 1932 nos. of signal lights points all over the streets of Dhaka City. The operational and maintenance cost of these lights is about 4 cores Taka. But this huge cost goes almost in vein, because in most of the cases the lights are not functioning now. The traffic police control the flow with the hands. In some cases traffic signals are found to be obscured by hoarding, billboards, branches of trees etc. Thus the influence of signal lights on traffic flow is almost nil (JBIC, 2000). 5. Environmental pollution in Dhaka Emissions inventory of mobile sources in Dhaka show that contributions of different vehicles dominate certain types of pollutants. Petrol-fueled light-duty vehicles (cars/ vans) and auto-rickshaws contribute 85% Carbon monoxide (CO), while diesel-fueled buses and trucks contribute 84% most of total Nitrogen oxides (NOx). Two- and threewheeled auto-rickshaws contribute about half of the total hydrocarbon (HC) emissions, while particulate matter (PM) emissions come mostly from diesel buses and trucks (45%), and auto rickshaws (40%) (ADB, 2006).

6 6. BUS RAPID TRANSIT (BRT) Bus Rapid Transit (BRT) is a very popular form of rapid transit implemented throughout the world. A recent Transportation Research Board study defines BRT as: "a flexible, rubber-tired form of rapid transit that combines stations, vehicles, services, running ways, and ITS [intelligent transportation system] elements into a fully integrated system with a strong image and identity." More generally, BRT includes at least some of the following elements, with the overall objective of reducing travel times. A number of transit routes use the transit way, with buses entering/exiting at either end of the transit way or at intermediate points. This permits the operation of a very flexible route network, which minimizes the need to transfer, providing a one-seat trip for a majority of passengers. (Guha R. 2011) 7. Methodology: First basic transportation data such as total number of different categories of on road vehicles, daily usage hour, run per day, characteristics of fuel used & fuel efficiency etc is collected from various sources like road transport authorities, vehicle licensing authorities, fuel distributors association, traffic police department, department of environment etc. Then appropriate emission factor is chosen to estimate the pollutant emission by using the simple formula: Daily emission (in ton/day) - [(No of vehicles)*(daily use of vehicle, in km/day)* (Emission factor, in g/km)]/ (1000) 2. Emission factor is available in the literature or some laboratory test may be conducted to select appropriate one. After introducing mass or para transit vehicle for example, railway or subway system, the number of car and other on street private vehicle will be reduced. Hence air pollution will also reduce. In this way environmental benefit can be estimated for introduction of rapid transit vehicles. For economic evaluation cost-benefit analysis will be done considering vehicle operating cost (VOC) and value of travel time (VOT). 8. Conclusion: The problem of traffic congestion and uncontrolled vehicle emissions make life miserable and causing threat to health and economic loss as well. Public transport service and air quality situation of Dhaka City is continuously deteriorating every year and imposing huge cost on the society. Though there is little information on human health, there is clear evidence that the air quality in Dhaka is harmful for the city dwellers and it is causing not only discomfort but also several diseases including allergy and asthma (Khatun, 2002). Such a problem needs immediate attention from the policy makers. As vehicle and emissions is a major contributor to air pollution, it is possible to improve air quality by reducing the vehicle stock through improving the public transport system service (BRT). Improved public transport facilities of the city could solve the transport and congestion problems, as well as improve the air quality. References 1. STP (2004), Strategic Transport Plan(STP) for Dhaka, Final Report, 2006, Dhaka Transport Coordination Board. 2. Rahman, S. (2008), Future Mass Rapid Transit in Dhaka City: Options, Issues and

7 Realities, Jahangirnagar Planning Review, Vol. 6, pp Japan Bank for International Cooperation, JBIC (2000), Study on the Improvement of Transportation and Environment in Dhaka, March, DITS (1994), Dhaka Integrated Transport System (DITS), Dhaka Transport Coordination Board (DTCB), Dhaka RMMS (2004), Road Maintenance and Management System (RMMS), Dhaka City Corporation (DCC), Dhaka ADB (2006), Country Synthesis Report on Urban Air Quality Management in Bangladesh,retrievedfrom f 7. Khatun, F.A Impact of Air Pollution on Human Health in Dhaka City. Proceedings of 1st National Conferenceon Environmental Health in Bangladesh, Environmental Program Bangladesh Poribesh Andolon (BAPA), February Guha, R. (2001), Pre-Feasibility of Bus Rapid Transit (BRT) and Metro Rail in Old Dhaka BSc Thesis, Department of Civil Engineering, BUET, Dhaka