noun
roundabout; traffic circle; rotary
A circular intersection where traffic flows around a central island. The term is neutral and used in traffic engineering and everyday driving contexts.
この町には新しい円形交差点ができた。
A new roundabout was built in this town.
円形交差点では、右回りに進んでください。
At the roundabout, please proceed clockwise.
ロータリー is a common loanword for a traffic circle, often used interchangeably with 円形交差点, but 円形交差点 is a more formal, descriptive term.
Compound of 円形 (circular) and 交差点 (intersection). The term is a straightforward description of a roundabout.