also: ラウンダバウト
noun
roundabout; traffic circle; rotary
A circular intersection where traffic moves around a central island. The term is a direct loan from English and is used in road traffic contexts.
この先にラウンドアバウトがあるので、注意して運転してください。
There is a roundabout ahead, so please drive carefully.
ロータリー is a more common Japanese term for a traffic circle, while ラウンドアバウト is a direct English loanword often used in road signs or by driving enthusiasts.
Borrowed from English 'roundabout'.