If people cycling have to deal with large roads and junctions, bi-directional cycleways are an important way of making it much easier to negotiate them.
This week's Good Facility runs around a large roundabout in the centre of Rotterdam. The cycleway is bi-directional, all around the roundabout, meaning people don't have to cycle all the way round it if they want to make a left turn (the equivalent of a right turn at a large roundabout in the UK). All movements for cycling have been simplified as much as they can be. This cycleway is the Dutch standard width of 4m, again with forgiving kerbing allowing full effective width.
Of course, it's questionable whether large roundabouts like this should even be built in city centres, but while they exist, they should be made as easy to cycle around, and across, as possible.