You'd be surprised how compact you can get a workable roundabout[0]. The brits have taken this to the extreme in some places,[1] Though I don't know effective a bit of paint is in actually making people treat it as a roundabout.
Actually I think traffic lights are better for very busy and/or very large intersections. But roundabouts are superior to four way stop sign intersections in every way. They don't even need to be all that large.
