Traffic jam

Have you ever been in traffic like this? If you haven't, then you're lucky. These cars in Jakarta, Indonesia are all stuck in a traffic jam.

Because there are so many cars on the road, they can't go fast at all. In fact, they often have to stop. It's the same as when there are a lot of people all waiting in line to get onto an escalator. When there are so many cars that they have to stop a lot, it's called stop-and-go traffic.

In some cities, it's like this every day. In the morning, everyone goes to work, and in the evening, everyone comes home -- all at the same time! This is the worst time to drive.