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World Resources 1996-97 (A joint publication by The World Resource Institute, The United Nations Environment Programme, The United Nations Development Programme, and the World Bank) (Data edited by Dr. Róbinson Rojas)
4. Urban Transportation IMPACTS OF URBAN TRANSPORTATION TRENDS
These urban transportation trends are exacting significant costs in cities in both the developed and the developing world. One is simply the direct financial cost of providing and maintaining the transportation infrastructure. Investing in the transportation infrastructure is essential for economic growth, increasing productivity and quality of life (43). Especially in the poorest developing countries, where the length of paved roadway per one million residents is 25 times less than that in developed countries, improving the transportation infrastructure is a key factor in providing access to jobs and establishing rural and urban trade links (44). However, inefficient operations and inadequate maintenance are translating into large financial expenditures without the expected benefits. In sub-Saharan Africa, for example, roads valued at almost $13 billion have eroded because of a lack of maintenance (45).
Transportation's environmental and social costs, although perhaps less quantifiable, are no less important, because they degrade quality of life and undermine urban productivity. These impacts include congestion, energy consumption, local and global air pollution, noise pollution, traffic accidents, and social inequities.
Congestion is perhaps the most visible manifestation of the failures in urban transportation planning. It undermines the central purpose of the automobile: ready access to people, goods, and services. Clogged city streets exact a major toll on economic productivity and exacerbate air and noise pollution.
In many cities in Japan, India, China, and Indonesia, peak period (rush hour) speeds in city centers consistently declined throughout the 1980s to the point that today traffic creeps along at less than 10 kilometers per hour (46). Perhaps the most notorious example is Bangkok, where peak period traffic speeds in the city center declined by an average of 2 kilometers per hour per year in the second half of the 1980s. As a result, an average car in Bangkok is estimated to spend the equivalent of 44 days per year stuck in traffic (47).
In developed countries, congestion afflicts large and small cities alike. A study of cities in OECD countries found that in virtually every city, speeds in the central business district have declined dramatically since 1970 (48). In the central business district of cities as diverse as Manchester, United Kingdom; Milan, Italy; Utsunomiya, Japan; and Trondheim, Norway, morning peak period speeds were 20 kilometers per hour or less in 1990 (49).
Congestion is frequently the result of an insufficient road network, and thus even a relatively few vehicles can cause intense gridlock (50). Yet, expanding the road network is rarely an adequate solution. In many cities in the developing world, such improvements are beyond a city's financial resources. In addition, road construction requires vacant land; in very dense cities such as Bangkok and Shanghai, China, additional road construction would require destroying existing buildings and/or displacing informal settlements. More important, any increase in road capacity tends to be quickly swamped by new travel.
Energy Consumption and Air Pollution
Transportation requires huge amounts of energy. Globally, 20 percent of all energy produced is used for transportation. Of this, between 60 and 70 percent goes toward moving people, and the rest toward moving freight (51) (52). In OECD countries, transportation uses an even larger share: about 31 percent of all energy used in 1991 (53). Transportation is heavily oil dominated; about half of the world's oil is consumed in the transportation sector (54).
Energy consumption in the transportation sector is expected to grow in both the developed and the developing world (55). From 1971 to 1992, worldwide energy use in the transportation sector grew on average 2.7 percent per year, faster than industry or other energy end use sectors (56) (57). This energy consumption contributes to both local and global air pollution and presents an economic burden, especially in countries that import energy resources.
Indeed, motor vehicles produce more air pollution than any other single human activity (58). Nearly 50 percent of global carbon monoxide, hydrocarbon, and nitrogen oxide emissions from fossil fuel combustion come from gasoline- and diesel-powered engines (59). In city centers, especially on highly congested streets, traffic can be responsible for as much as 90 to 95 percent of the ambient carbon monoxide levels, 80 to 90 percent of the nitrogen oxides and hydrocarbons, and a large portion of the particulates, posing a significant threat to human health and natural resources (60) (See Table 4.2.)
In the cities of the developed world, car emissions pose the greatest threat to air quality. In the United States in 1993, transportation sources were responsible for 77 percent of carbon monoxide emissions, 45 percent of nitrogen oxides, 36 percent of volatile organic compounds, and 22 percent of particulates (61). In the European Union, pollution control measures have been initiated over the past 20 years to reduce nitrogen dioxide levels, but these measures have been offset by increases in the numbers of vehicles on the road (62). In the United Kingdom, for example, average concentrations of nitrogen dioxide increased by 35 percent from 1986 to 1991, mainly as the result of increased emissions by motor vehicle traffic (63).
In the developing world, automotive air pollution is mostly a problem in large cities with high levels of traffic, such as Mexico City, Bangkok, and Lagos, Nigeria. In other cities, power plants, factories, and other stationary sources still constitute the greatest threat to air quality. However, even in some smaller urban centers such as Peshawar, Pakistan, and Kathmandu, Nepal, air pollution from motor vehicles is becoming an increasing problem (64).
Motor vehicles are also a significant factor in lead emissions. An estimated 80 to 90 percent of lead in ambient air is d erived from the combustion of leaded gasoline . Recognizing the health threat, most developed countries have reduced the lead content of gasoline over the past decade. Unleaded gasoline has been introduced in most Latin American countries, Malaysia, Singapore, Taiwan, and the Republic of Korea, although in most cities of the developing world, ambient lead levels still greatly exceed the health standard of 1 microgram per cubic meter (65). In Cairo, for example, ambient lead levels of 1.5 micrograms per cubic meter are common (66) (67). Lead levels tend to be especially high along roads with heavy traffic density (68).
The impacts of motor vehicle emissions extend far beyond the local area. The transportation sector is the most rapidly growing source of greenhouse gas emissions--that is, emissions of chemicals that have the potential to contribute to global warming (69). These include carbon dioxide, chlorofluorocarbons, nitrous oxide, and carbon monoxide (70). In 1990, about 22 percent of carbon dioxide emissions from fossil fuel use came from the transportation sector (71). OECD countries are responsible for about 70 percent of greenhouse gas emissions attributed to transportation (72). However, the share of emissions from developing countries is expected to rise in the future because of the growing sizes of their motor vehicle fleets and their use of less efficient fuel-burning technologies (73) (74).
Traffic noise--from the constant drone of passing cars and trucks to the sound of screeching tires, blaring horns, radios, and car alarms--is extensive in urban areas. Noise pollution can damage human hearing and affect psychological well-being, as well as decrease property values (75). An estimated 100 million people in OECD countries are exposed to traffic noise in excess of 65 dB(A) (higher than the 55dB(A) considered acceptable) (76). Although data for developing countries are scarce, data collected along heavily traveled roads in Bombay, India, indicate sound levels of 65 to 85 dB(A) (77).
In 1993, an estimated 885,000 people died in traffic accidents (78). The majority of these deaths were in the developing world, and traffic accident deaths are a leading cause of death among people in economically active age groups (79) In India, for example, roadway death rates (road deaths per 1,000 vehicles) are 18 times higher than those in Japan, amounting to 60,000 fatalities per year (80). In general urban traffic and pedestrian accidents form a higher proportion of accidents in developing countries than in developed countries (81).
Each year in the European Union, 55,000 people are killed, 1.7 million are injured, and 150,000 are permanently disabled as a result of traffic accidents (82). In the former East Germany after the opening of the Berlin Wall, the sudden increase in automobile use is cited as a primary factor in the doubling of traffic fatalities between 1989 and 1991 (83).
The dispersed patterns of many of today's cities, made possible by the availability of motor vehicles, contribute to social inequities as well--chiefly, limited access to jobs by the urban poor as well as proportionately higher travel costs. These problems exist in cities in both the developed and the developing world, although the causes and symptoms are somewhat different.
In the United States, suburban flight has left the urban poor concentrated in city centers far from jobs, stores, and entertainment services that have relocated to the periphery as well. Unable to afford cars, many poorer dwellers in the city center must rely on public transportation that rarely adequately serves the suburbs. This has played an important role in limiting job and income opportunities (84). In Detroit, for example, about 40 percent of the central-city population does not have a car, yet most of the new jobs in the region are in outlying suburbs (85) (86).
In cities with large segments of low-income groups in squatter settlements at the periphery of the urban area, similar forms of isolation and inaccessibility exist because opportunities for employment, advanced education, recreation, and shopping are often located in wealthier areas in the city center. In Santiago, Chile, the poorest residents tend to live on the urban periphery. The majority of their trips are over long distances, and they must travel by relatively inconvenient modes, either by public transportation or on foot. For those in the richest sections of the city, the majority of trips are over shorter distances and are made by privately owned automobile (87). In Sao Paulo, poor people can spend 2 hours or more traveling between home and work (88). Similar disparities exist in many Asian and African cities.
Members of poorer households also tend to spend a larger percentage of their income on travel than do members of wealthier households (89). In household budgets, the cost of the breadwinners trip to work is usually the top priority, which sometimes means that trips for schooling or health services must be sacrificed (90). In Dar es Salaam, Tanzania, many residents cannot afford bus fares, and even a bicycle costs, on average, about four times the monthly minimum wage (91). Thus, access to affordable transportation services can greatly improve the welfare of many poor families.
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