an eyeball-to-eyeball confrontation is what it has been all about; proponents of modern transportation and the growing global environmental movement are the protagonists. While the former see personal mobility (read modern means of transport) as an expression of freedom and essential to economic progress, the latter view the same as a source of social and environmental ills. The truth lies somewhere in between.

That the transport sector imposes severe negative impacts on the environment is a fact. M J Quinn, in the 1993 World Bank paper What"s Wrong With Trans-port and the Environment? goes so far as to state that transport itself is a "cost". The aim of environmentally sustainable development is to reduce such costs, while increasing the benefits, or at least holding costs constant.

Transportation spending as a percentage of domestic spending is high and rising in most countries. Historically, transport costs have barely reflected internal costs (like road construction and maintenance) and external costs (like environmental costs). The Organization of Economic Co-operation and Development"s (oecd ) calculations point to the fact that transport subsidies increase environmental and social expenses.

A fundamental shift is underway in the global motor industry. Until 1990, oecd nations accounted for 90 per cent of the 50 million cars sold worldwide. In the coming years, saturated markets in these countries are expected to grow very slowly. For instance, Japan"s eight per cent car growth through the "80s is likely to be less than two per cent for the rest of the decade. In contrast, the growth areas are expected to be the developing countries, especially in Asia where demand is growing at seven per cent per annum (car sales are rising at the rate of 10 per cent annually in Thailand and China).

Global trends in service industries have exacerbated transport growth. Distances travelled are increasing, leading to urban sprawl. Each improvement in transportation services increases migration to urban areas. Traffic, measured in terms of vehicle-miles per year, is increasing at the rate of three per cent annually. Clearly, human and automobile populations are linked. But the impact of today"s annual output of 48 million cars on the environment vastly exceeds that of the annual human population growth of 90 million.

Most countries (and institutions) lack a comprehensive transport policy; until recently, transportation policies were focussed on freight transport to fulfil economic targets. Furthermore, all transport is unimodal (automobiles and trucks)-oriented. The example of the European Community illustrates the consequences: over the last 20 years, while road freight transport has more than doubled in absolute terms, the relative share of all other modes (including pipelines) has decreased; passenger transport activity (passenger-kms) has increased by more than 85 per cent in the last 20 years, mostly due to private car use; and, between 1970 and 1989, the volume of road traffic (vehicle / kms) doubled both for private and freight vehicles.
Taking the "eco-toll" Energy consumption engenders the principal environmental impacts of transport. The transport sector accounts for roughly one-third of the total energy consumed worldwide; within developed nations, automobiles account for over half of the carbon dioxide (co₂ ) emissions. For each gallon of fuel consumed, approximately 19 pounds (8.5 kg) of co₂ (equal to 5.3 pounds, or 2.4 kg of carbon) are emitted into the atmosphere.

Alarmingly, co₂ emissions from motor vehicles in developing countries, which account for 30 per cent of global co₂ releases, are increasing at the rate of 3.5 per cent annually. Overall global vehicular co₂ emissions are increasing by 19 million tonnes per annum; if present trends continue, vehicular emissions will increase 50 per cent by the year 2010.

The very multiplicity and mobility of transport, which make it convenient, also present it as a potent polluter, embracing a wide array of pollutants including noise, vibration, greenhouses gases, lead and waste streams (tyres, oil, discarded vehicles), all of which combine with depletion of natural resources (oil, metals, aluminium, rubber) to wreak havoc on the ecology.

In urban areas, road traffic accounts for a significant amount of air pollution (90-95 per cent of carbon monoxide and lead, 60-70 per cent of oxides of nitrogen and 40-50 per cent of hydrocarbons). Mexico City is the most polluted city in the world, with an estimated 12,500 deaths per year and 11. 2 million lost work-days due to high particulate levels. Lead poisoning has been believed to result in 140,000 children requiring remedial education. Also, an estimated 46,000 adults suffer from hypertension borne of lead poisoning, of whom 330 die each year from heart attacks. In Cairo, Egypt, lead concentration in the air is five-six times greater than global norms; lead content levels in the blood of children of Cairo is three-five times more than that of children in rural Egypt.

The disposal of 40 million unserviceable cars every year exerts enormous strain upon environmental sinks. Mountains of used automobile tyres testify to the problem. A small fraction of junked cars are being recycled, but it is a costly undertaking. One solution is forcing manufacturers to play a more active role in recycling their own products or to manufacture them in such a manner that recycling becomes more profitable. Volkswagen and bmw , both of Germany, began this effort in 1993, reducing the number of types of plastic used from about 300 to 20, and making disassembly and recycling easier in their new plants.

The transport infrastructure imposes permanent and often irreversible effects on land-use, such as loss of agri