Actually, in some cases, lights on a roundabout are a DAMNED good idea; where I join the M61 just outside work (see HERE) is having them fitted - there's at least a couple of shunts a week there, and some quite serious accidents. Basically, it's a roundabout with poor visibility, quite a lot of exits/entrances, and drivers tend to enter it at way too high speed. That, plus the fact that it's difficult to get onto at peak times results in crunches, tailbacks and aggro just about every evening. They're putting lights in now (YAY! for the Highways Agency...and I'll bet you don't hear THAT very often), and I for one will be damned glad when they have.