[NJARC] Traffic Circles

[donald ball]

 Can somebody please tell what the difference is between a "traffic 
circle", a term
that all of us seem to understand, and a "roundabout"?   This is NOT a 
joke that I
am promulgating, I just don't know what difference there might be.  Both 
serve
the same functions of traffic control by directing traffic into a 
circular pattern and
have multiple exits.

What's the difference? (Besides the about 80 years since the design and 
naming.)

Don Ball