The Basics

Everyone on the planet uses some form of transportation every day. People walk, bike, skate, take buses or trains, drive cars, or hop on planes or boats to get where they are going. And not just people - products are transported all over the world, too.

How people travel often depends on how their communities are set up. People who live in large cities with reliable subway systems (like Boston, Massachusetts; Washington, D.C., London, England, and many others) find that the subway is the best way to get around downtown due to things like parking restrictions and driving hassles. People who live in communities with good bus service will often choose to take the bus instead of driving. Convenience and cost are usually the deciding factors for most people.

So what's the big deal? Well, most of the major forms of transportation - or transporting goods - produce air pollution. Cars, trucks, trains, boats, buses, motorcycles, etc., all have an impact. Some have a greater impact than others - it depends on several things:

• the type of engine (including the emissions control systems),
• the type of fuel, and
• the ratio of people in the vehicle to the total air pollution it produces.

After you're familiar with the basic fuels and engines, check out the section on this site that describes how vehicles produce air pollution - and which ones are the worst offenders.

In most places in the United States, the primary form of transportation is driving, alone, in a car. This is because most communities are designed specifically for cars, making it inconvenient for many people to walk, bike, or bus to their destinations. Unfortunately, driving alone in your car is also one of the most polluting ways to travel.

Outside the U.S., there are still many countries where people walk many miles every day, or ride bicycles as their primary form of transportation. For these people, often the cost of a car is too great, and/or the road conditions are too poor for them to consider anything but walking and biking. In most places in the world, in fact, according to data gathered by the American Automobile Manufacturer's Association, the average "person to car" ratio is at least 10 people per car, and many countries have a ratio of 100 to 1,000 people per car. The world average is about 11 people per car, but this number is greatly affected by countries like the United States, which has a person to car ratio of 2 people per car.

These ratios are derived by taking the entire population of people in the country, and dividing that number by the number of cars in that country. So the U.S. number (like the rest) includes children, the very elderly, etc. - and many of these people don't or can't drive!! Which means that many U.S. households have not one car, but several.

The least polluting way to get around is low-tech: biking, walking, skating, etc. And even if you only leave the car at home a couple of days a week, you'd be surprised at what an impact you can make.

There are some good things coming down the pike. Check out the other sections of this site that...

• introduce innovative new technologies that are here now or on the way, and
• profile real people who have pioneered vehicles like electric cars and cars that run on old kitchen cooking oil.