> All roundabouts prevent vehicles from just blowing straight through the intersection in the desired direction without so much as slowing down Not at all. A l

> All roundabouts prevent vehicles from just blowing straight through the intersection in the desired direction without so much as slowing down Not at all. A large enough roundabout with good visibility from the approach can allow you to traverse it without slowing down at all - if the speed limits coming up to the yield line are appropriate, and traffic is flowing. There's a sense in which a roundabout is just a short circular section of highway with a series of on and off-ramps around the edge. Well designed onramps allow you to merge without slowing, and off-ramps let you leave without disrupting traffic. Roundabouts can permit the same.