What are traffic waves?

Traffic waves are when cars start to slow down and then speed up again, like a wave in the ocean.

Imagine you're riding your bike on a path with other kids. Suddenly, one kid slows down because they see a puppy. The next kid notices and slows down too, and so on, it's like a chain reaction. Then, when the puppy runs away, everyone speeds up again! That’s what happens in traffic waves.

In a busy road, if one car slows down, the car behind it has to slow down too. This keeps going all the way back, like a ripple in water. Sometimes people brake suddenly or change lanes, which can start a whole wave of slowing and speeding.

It’s not because of magic, it's just how cars follow each other. If everyone keeps a good distance and drives smoothly, traffic waves don’t happen as much. But when people drive close together and brake suddenly, it makes the waves bigger!