Definition
In Korea, a roundabout is an intersection with a circular island in the middle, where cars travel in one direction around it to get through. In countries like Korea where cars drive on the right, traffic circles counterclockwise. With no traffic lights, two simple rules keep traffic flowing smoothly: cars already in the circle go first, and you use your turn signal.
Cars Already Circling Go First
Picture getting on a merry-go-round at an amusement park. To avoid bumping into the people already riding, the people waiting outside have to stop first and look for an empty spot. A roundabout works the same way.
A car about to enter must slow down or stop at the yield line painted on the pavement outside the circle. Cars already circling inside have the right of way. Cars in the circle should still slow down and watch for entering cars. The whole intersection stays clear only if the flow inside the circle never stops.
If an entering driver pushes their nose in too aggressively, the circling car has to slam on the brakes. That can cause a chain of cars bumper to bumper around the whole circle, and then a bottleneck locks up the intersection. The basic move is to slow down, wait for the circling car to pass, and go in when you see a comfortable gap.
One Blinker Says It All
Most roundabouts have no traffic lights, so your turn signal is the only way drivers can talk to each other. If you move without signaling, other drivers can't tell where you're headed, and the risk of a crash goes way up.
When you enter, turn on your left turn signal to show you're merging into the circle. Like the right signal on the way out, this is a duty set by Korea's Road Traffic Act. It tells the cars behind you and the cars already circling that you're about to join the flow.
When you leave, turn on your right turn signal just before the exit you want. Once they see it, the next car waiting at the entrance can safely pull into the circle. This small action keeps traffic moving faster for everyone.
A Closer Look: It's Not the Old Rotary
Many people think the old-style "rotary" and the modern roundabout are the same thing. They're actually very different road systems, designed with opposite priority rules.
In the old rotary, entering cars had priority. Cars already circling had to stop and yield to them, and the whole circle often froze up completely.
Modern roundabouts work differently. The entrances are curved so cars have to slow down, and a yield line is painted on the road. By giving circling cars the right of way, they cut down on traffic jams. According to analysis by Korea's Ministry of Land, Infrastructure and Transport, installing roundabouts cut crashes by about 25% and casualties by about 33%. Smaller roundabouts showed even bigger benefits.
Common misconceptions
At a roundabout, whoever pushes their nose in first gets to go first.
It doesn't matter who got there first. Cars already driving in the circle have the right of way. Entering cars must stop and wait at the yield line.
A roundabout and a rotary are just two names for the same road.
A rotary gives priority to entering cars and encourages high speeds. A roundabout gives priority to circling cars and is built around slow speeds and yielding, so it's a completely different design.
Where you meet it
You're circling a roundabout, turn on your right signal, and safely exit at the street you want.
You slow down at the entrance and wait at the yield line until the white car circling inside has passed.
In one sentence
The basic rules of a roundabout are "circling cars go first" and "left signal to enter, right signal to exit."