We have back-to-back round-a-bouts in Chattanooga (153 / Lake Resort / Access) which have two loops (concentric inner & outer round-a-bouts)... that can be quite confusing for anybody unfamiliar with the local pattern.
I would do everything possible to avoid this UK Round-a-bout — nothing Magical about it having three concentric lanes just in its inner loop! =P
Ours is much simpler, with a round-a-bout on either side of a regional highway. One of the difficult parts about it is everybody is already jacked the fuck up (on account of 2 of the 5 input/outputs being extremely steep grade to enter/exit a river-crossing, with speeds averaging 65-70mph ["55mph" posted, oklol).
Oh, I've re-read and you just mean there are two fast paced roundabouts that are close by and they both have two lanes around them.
That wouldn't raise an eyebrow here in the UK, it's very normal for highway junctions to have on/off ramps that end in 2-3 lane roundabouts, one each side of the highway.
