Wheeling here, wheeling there, bicycles are everywhere! At least, they used to be. A new report says fewer and fewer people ride these two-wheeled wonders.

Bicycles are low-cost and easy to use. Repairs are simple. Yet all over the world people have parked their bikes. Instead they climb into cars, buses, and trucks. In many places, even poor people use cars or motorcycles instead of bikes. Why do you think this has happened?

Researchers at Johns Hopkins University were curious too. They compared bike ownership levels over the last 25 years. They studied over a billion households around the world. That’s a lot of wheels!

Soon, patterns emerged. People in northern Europe own the most bikes. People in parts of Africa and central Asia own the fewest—except for India and China. Bike ownership there is very high. The big numbers from those two countries hurt the study results.

But researchers fixed the problem. They took China’s and India’s bikes out of the study. The new results show that fewer than one in three households in the world own a bike. In more than 148 countries, bike ownership has dropped.

But why? So far, researchers haven’t solved the mystery. Officials in many places try to encourage people to ride bikes. They point out the lack of pollution and traffic. They say bikes also help people stay healthy. Some cities even take away car driving lanes and give them to bicycles.

Still, some people think of the lowly bicycle as something to play with, not a way to get to work or do business. How do you see bikes—travel tools, or toys?