As an often pedestrian, i often prefer lights. If it's a busy dual carriageway roundabout It can often be hard to route pedestrians across. You end up with elaborate and winding pedestrian subways.

Roundabouts are ok on rural junctions, but round here we often have to have traffic lights on roundabouts as you start to get closer in to urban areas - and they do seem to help flow.

I just don't believe road design alone can remove the need for coordination as population density gets above a certain level. Fuck in central London you need traffic lights just to coordinate all the buses never mind cars. Of course they need an overhead s-bahn type light rail system there though, but planning rules/landowners won't allow it. At this point they just need less people - but again the govt/electorate/landowners won't allow that because they're all a bunch of tw4ts.