*LET A LOCAL CHIME IN HERE, OK?*
The US 41/Breezewood-Bell interchange in Neenah, WI (about ten minutes south of Appleton) was a total clusterf*** in its previous life. Four signalized intersections in very close proximity, two frontage roads and the two interchange ramps. Breesewood Ln/Bell St (the street changes its name at the interchange) is a very busy street. The intersections ALL had very high numbers of vehicles making turns and traffic backups were very common, even after midnight. Often, to go from SB US 41 to NB Harrison St (the east frontage/access street), I had to stop twice at red lights in that mess and to turn onto NB Harrison St often required waiting two and even three cycles.
Since the rebuild, even though traffic counts are about the same as before, it is like 'where did all of the traffic congestion go?'. About four out of every fives times that I go through there now, I get though with zero stops and delays, only having to slow down to make the turns. The difference is like that between night and day and it is working well beyond anyone's wildest dreams..
There is also an older roundabout on Breezewood Ln at a local street intersection several blocks west of the interchange area.
BTW, before WisDOT decided to go with the roundabouts there, their favored concept was for the interchange ramp intersections to be redone as a SPUI.
Also, last year, WisDOT redid US 41/9th Ave in Oshkosh with a similar four roundabouts - and with similar results.