慣性式汽車制動(dòng)實(shí)驗(yàn)臺(tái)設(shè)計(jì)

慣性式汽車制動(dòng)實(shí)驗(yàn)臺(tái)設(shè)計(jì),慣性式汽車制動(dòng)實(shí)驗(yàn)臺(tái)設(shè)計(jì),慣性,汽車,制動(dòng),實(shí)驗(yàn),試驗(yàn),設(shè)計(jì) 1 Vehicle Inspection and Maintenance Policies and Programme Sri Lanka1 1. Introduction The active road vehicle population of 1,023,000 in 2000 has consumed 660.2 million liters of diesel and 278.40 million liters of petrol. Railways have consumed 399.9 million liters of diesel in 2000. The estimated base data of annual emission from the transport sector for year 2000 has been estimated as follows; CO 2.014 million kg NOx 0.290 million kg SOx 1.231 million kg Aldehydes 1.053 million kg The Government of Sri Lanka (GOSL) has implemented the Ambient Air Quality program in the city of Colombo establishing two fixed air quality monitoring stations; one in area where high density of transport sector air pollution occurred (Central Business District of the City of Colombo called Fort) and the other in a low density transport zone (Meteorological Dept. Site). One mobile unit is available to monitor the area where needs arise. These stations were given by the Ministry of Transport and Environment (MOTE) to the Central Environment Authority (CEA) for continues monitoring. Average age of the active vehicle fleet is 6.2 years, which is relatively higher compared to international standards. In general, Sri Lankans have poor maintenance practices. It is now estimated that around 12,000 motor cars have converted to LPG, which is considered as an environment friendly cleaner fuel, however, no regulations are passed by the GOSL on the safety of the registered LPG driven vehicles by the Commissioner of Motor Traffic (CMT). The main constraint emerging is that the lack of appropriate vehicle maintenance and proper vehicle testing program at the point of registration or issuing the roadworthiness certificate. There is investment constraint to upgrade the vehicle fleet, to have more fuel efficiency vehicles and to use the environment friendly vehicles. Pricing policy of the country has influenced to have second graded fleet (used vehicle) and low fuel efficient vehicles with poor conditions (e.g.: increase of small diesel vehicle fleet, increase of low fuel efficient re- conditioned vehicles and high consumption of diesel fuel). The pricing policy and nature of monopoly market (oil company own by the government) of major petroleum product has distortion demand for fuel, further to supply high sulfur diesel and leaded petrol. The details are discussed in proceeding sections. 2. Fleet Structure and Emission Levels The vehicle ownership ratio in Sri Lanka was 28:1 in 1991 and reduced to 20:1 in 2000. Per capita petrol consumption has increased from 12.7 liters in 1991 to 15.9 liters in 2000. The per capita diesel consumption has increased from 28.7 liters in 1999 to 54.7 liters in 2000. This shows that per capita petrol consumption has increased by 23% and per capita diesel consumption by 92%. The past decade of steady economic growth has resulted in sharp changes in the fleet mix. For example, Graph-1 highlights the changes in taxi service: imports of 3-wheelers from India started only after liberalization in 1978 but have grown rapidly during the 1990s. In the early 1980s typical Colombo Taxi was an aged Morris Minor, replaced after liberalization by reconditioned second-hand Japanese cars: the number of petrol taxies peaked at around 8,700 in 1991, falling to 5,900 by 1997. Clearly the recent explosive growth of 3-wheelers has met a need 1 Jayaweera, Don S. Ph.D. in Transport Planning , MIT,USA, M.Sc.(Town (2) S.M. Zaidi, Country Experience of Pakistan in improving fuel quality; (3) Yangsheng, Improving Fuel Quality in China One factor remain is that vehicle inspection system has to be included emission test taking sulfur level of diesel and other fuel quality. 4. Current Environment Policies related to the Transport Sector Transport sector has continued to be expanding in response to the economic development during the post-independent, and especially during last two decades with the expansion of motorization. The transport sector contributed 8.5% to the GDP in 2000, which shows a significance of the transport sector activities within the national economic activities. Transport in itself is a significant part of the national economic activity, while it also impinges upon the performance of all other sectors, and thereby plays an important role in attracting foreign investors and industrial growth. This sector has recorded an average growth rate of 6.4% during last decade. It provides direct and indirect employment to around 550,000 2 persons with the state sector accounting for direct employment of 100,000 persons. The public expenditure on the sector has increased by 225% during last ten years, private investment increased by 200% for the same period. Sri Lankas transportation network covers 100,000 km of roads, and 1,467 km of rail network, 64 billion of passenger km, and 7 billion of freight tonne km by road, rail, air and sea, and the stock of active 900,000 road vehicles and rolling stocks of railways. The length of “A” and “B” class 2 Ministry of Transport, “Progress”, March, 2001 5 “national road” network has risen from 6,518 km in 1948 to 11,648 km in 2000. 3 In addition, there are 15,000 km of class “C” and “D” roads labeled as provincial roads, and further 77,000 km of class “E and local access roads (i.e. bridle paths) that are generally earth and partly gravel roads. On the other hand, the rail network of 1,435.7 km in 2000. Efficiency and effectiveness of the transport network and systems are a primary requirement for the economic development in the country. Over the past 30 years, however, the transport fixed infrastructure and services lagged behind relatively to the some of other sectors in the economy, especially in respect to the condition of road network, and the rail services. The average roughness of the national road network has increased from 4,200 Bump Indicator (BI) value in 1982 to 6,500 in 2000 which was the result of rapid growth of traffic demand and railway passenger market share has been reduced 22% in 1980 to 6% in 2000 4 . Much of the environmental issues related to the transport sector in Sri Lanka are associated with urban environment, and have been reported from the Colombo Metropolitan area and Kandy urban center which is the second largest city in the island. Of these, air pollution due to vehicle emission, exacerbated by traffic congestion and condition of the fleet are two of the major issues that have emerged in recent years. The other problem are the poor quality of land use development hampering the quality of pedestrian environment, noise pollution due to road traffic and poor drainage which inhibits vehicular and pedestrian traffic after heavy rains. There are also more indirect, but nevertheless vitally important, problems such as the destruction of biological diversity (in biological rich areas) and environmental degradation during road construction. Another problem given scant attention in this sector is the entry of alien species via shipping and air transport. The impact of road damage due to global warming and sea level rise, and its impact on the transport network, may also be considerable and has been dealt with previously under impacts of climate change. The Colombo Urban Transport Study (CUTS) has been conducted through the Colombo Urban Transport Project (CUTP), implemented by the Colombo Urban Transport Planning Center of the then Ministry of Transport and Highways, as a follow up activity to the Metropolitan Environment Improvement Program (MEIP). Several activities of the Clean Air 2000 Action plan are included in the CUPT. The problems concerned with transport are mainly in relation to the Colombo Metropolitan Region. According to the CUTS the main source of air pollutants from the transport sector is vehicular emissions, compounded by traffic congestion. At present, the national pricing policy of fuel promotes the use of diesel, which increases air pollution, but although it has been recommended that the pricing policy be revised to address this problem, no clear policy decision has been effected to date, mainly due to the increase in cost of living that would follow. There is also no policy for restricting vehicle imports in a bid to reduce congestion in the city as yet, although this too has been recommended. However, several important initiatives are underway to alleviate road congestion in Colombo through improvement of the network. This aspect also needs to be addressed in other cities such as Kandy. The problems of flooding and drainage in Colombo are also addressed through the plans for future development of the Colombo City. Policy measures have given rise to the introduction of EIAs and IEEs to minimize the damage caused to the environment during road construction. A main deficiency in this is that EIAs are required only when establishing roads over 10 km, which other roads necessitate only an Initial Environment Examination. 3 Transport Statistics- Sri Lanka, 2001, Ministry of Transport 4 Jayaweera, Don S.” Transport Sector charges and Prices” ESCAP, December, 2000 6 Policy measures have been introduced to remove un-roadworthy vehicles from the roads, but this is not implemented due to the paucity of a strict vehicle inspection and licensing scheme. Measures were also to be introduced by the government to limit the number of private vehicles entering the city of Colombo to control congestion, but this was not practical due to the limited public transport facilities within the city. Under the Clean Air 2000 Action Plan, several actions have been recommended to provide solutions to many environmental problems related to transport. One of the positive developments in terms of reducing the air pollution from transport vehicles includes the phasing out of leaded petrol by the year 2010, although the target of unleaded petrol in the market by 2000 has not been met with. Secondly there is a trend for a switch to Liquid Petroleum Gas (LPG) from petrol, but this is not due to a national policy, but due to lower price of LPG. Policy measures are also lacking in terms of addressing the poor quality of the pedestrian environment and the problem of loud intermittent noise from horns, compounded by the lack of a standard specification for horns. Further, there are no controls in force to regulate noise from traffic near sensitive areas such as hospitals and schools, or policy that precludes the location of such institutions (particularly hospitals) near roads with heavy traffic. 5. Environmental Issues in Road Transport and Future Programme Vehicle maintenance is a widespread problem in Sri Lanka, as in other South Asian countries, and one that contributes towards air pollution. Although policy measures have been introduced to remove old vehicles from the roads, strict vehicle inspection and licensing do not happen due to technical and procedural deficiencies of the systems. These procedures need to be reviewed to better understand the constraints that underlie their failures and to identify improvements in enforcement measures. The government policy of importing second hand reconditioned vehicles for economic reasons has also aggravated the proliferation of poorly maintained vehicles. Despite the regulations, many of these vehicles are more than three years old, have done considerable mileage, and have high emission rates. Further, 17,500 private sector bus fleet consists of 78% of re-condition and more than years old buses. Hence, the introduction of proper vehicular inspection and maintenance programs is a vital requirement to reduce the load of air pollutants being released into the atmosphere. Vehicle maintenance facilities are also often limited by lack of skilled labor. Hence, mobile training programs for motor mechanics in Colombo on better vehicle maintenance could be of considerable assistance to reduce vehicular air pollution. The practice of using smoke meters to check air pollution should also be continued with the collaboration of relevant government departments, the traffic police, the Provincial and Local Authorities, and the private sector. It has also been suggested that exhaust emission certificates issued by an authorized institution could be linked to the vehicle insurance scheme to motivate owners to engage in better vehicle maintenance practices. 5.1 Low capacity for monitoring vehicular emissions A prerequisite to address the issue of vehicular emission is the availability of reliable emission data over a period of time, but availability of data on vehicular emissions has been limited in the past. This is now being addressed through a World Bank sponsored state programme for monitoring the ambient air quality in Colombo. However, much of the available data, as well as monitoring facilities, have been limited to Colombo, although there are plans to expand monitoring to other locations in the country. Further, due to the high cost involved in maintaining the three stations that are in operation in Colombo at present, it has been found to be necessary to use low cost standard methods to expand the monitoring of air quality levels in and outside the urban environment of Colombo. 7 5.2 Condition of the road network, Road Furniture and Traffic Management A major problem in the transport sector is that the condition road network, road furniture and traffic management schemes have not been maintained, developed and expanded sufficiently to accommodate the increasing importance of vehicular traffic and the rapidly growing vehicle population, coupled with the lack of an alternate efficient transport system such as the railway. This has given rise to heavy road congestion in Colombo during peak hours, which has a direct bearing on the rising levels of air pollution in the city, particularly during peak traffic hours which also expanded from one and half hours to three hours. The unplanned land use and transport plan lead to concentration of industrial and commercial activities, schools, hospitals, and courthouses in Colombo has added to the problem of traffic congestion in this city. The general unsatisfactory condition of the present road network has been a serious impediment to the expansion of economic activities. According to estimates made by the Colombo Urban Transport planning Center of the (then) Ministry of Transport and Highways, the cost of congestion in the Colombo Metropolitan Area had increased from SLRs 252 million in 1992 to SLRs 520 million in 2000. It has been recognized that the introduction of measures to ensure a smooth traffic flow could considerably increase fuel efficiency and help reduce air pollution, and successive governments have taken several initiatives to reduce traffic congestion in Colombo. These include installation of automatic traffic signals-where traffic jams are frequent-to regulate traffic flow, the shifting of the administrative capital to Sri Jayewardenapura Kotte, and the staggered opening and closing times of government and private establishments, factories and schools. However, none of these have had the desired effect of reducing traffic congestion in the city. Measures to reduce traffic flow into Colombo by limiting the number of private vehicles entering the city and employing luxury buses to deal with internal transport have been considered but not put into operation due to various constraints. More recently, several physical means have been introduced to relieve road congestion. These include the two fly-overs being constructed over the railway lines at Dematagoda and Ragama in the Colombo Metropolitan Area; the construction of a new bridge over the railway line at Maradana, and establishment of pedestrian crossings and bridges to regulate pedestrian behavior; and the construction of the Kelani Bridge over the Kelani river to ease traffic congestion among vehicles coming to Colombo along the Kandy and Negombo roads. There are several other main road projects due for implementation to improve the road network and to ensure a smooth flow of vehicular traffic. The Marine Drive and extension of the Duplication Road projects are already in progress and the Colombo-Katunayake expressway from the new Kelani Bridge to the Katunayake Airport is due to commence. The construction is scheduled to commence in 2001 for Matara-Colombo expressway and Colombo Outer Circular Road (which will link all major roads radiating from Colombo), is in progress, while the feasibility study for the Colombo-Kandy expressway is now in progress. 5.3 Poor state of roads and pavements The poor quality of road surfaces has been identified as one of the reasons for several transport hazards, including contributing towards road congestion. The maintenance and development of class A and B national roads and 4,480 bridges are vested with the Road Development Authority (RDA); class C and D roads are under the purview of provincial councils, while the other roads are maintained and developed by Local Authorities and other government and private institutions. Although the road density and coverage is relatively better in Sri Lanka compared to other developing countries, the condition of roads, particularly the provincial and local roads, have not 8 kept abreast with the growing demands for transportation, mainly due to resource constraints. For instance, about 88% of roads under class C,D, and E are poorly maintained. Provisions for pedestrians have also continued to be poor due to the inadequacy of footways, zebra crossings and controlled crossing points that are either signalized or have barriers in the central reserve to channel pedestrians. Another problem is the poor state of the pavements, exacerbated during the rains due to poor drainage in the cities. The Road Development Authority has implemented a number of foreign projects for better maintenance of national road surfaces during 1999, and 2000 under the periodic maintenance programme. However, almost all funds available last year have been used for rehabilitation, widening and construction of roads, while only about 5% was left for general maintenance of roads and bridges. The RDA is continuing its road rehabilitation and reconstruction of bridges programme in the Southern, Central, Western, and NorthWestern provinces, and some allocations have also been made for maintenance and development of provincial and local roads. Despite these initiatives, many of the roads need better maintenance and repair, especially the smaller roads in the city suburbs and rural areas, while it is evident that most highways in the Colombo Metropolitan Area are operating at, or near, total capacity especially during peak traffic hours. Beginning from large-scale changes in the natural environment with the building of the first road in Sri Lanka by the British in 1821, road building has had varying environmental implications such as destruction of biological diversity, dust and noise pollution. In order to minimize the adverse environmental impacts of road development it is required that Environmental Impact Assessment studies are done prior to commencement of such projects. However, only road projects over 10 km in length are covered under this requirement, while other important features such as conserving the trees and natural landscapes or components of biological diversity in the area; the vehicle population density; the human population in the area to be developed, etc. are generally not taken into account. A number of road projects being implemented in the Colombo Metropolitan Region at present have given rise to environmental issues such as compensation for lost property and community facilities, noise and air pollution, and damage to cultural, religious institutions in the vicinity. Another problem is the poor attention given to drainage and flooding, and to canals and drainage out falls during development activities. It is also important that road design supports the canal and drainage rehabilitation programs