Signalising roundabouts can improve safety for people on bikes riding on-road at roundabouts.  Generally only multi-lane roundabouts will be signalised because of the increase in capacity that signalisation offers. Single lane roundabouts, which may already offer a suitable cycling environment, would likely be converted to two lane roundabouts before considering signalisation. Signalisation may assist with reducing vehicle speeds and increasing safety for cyclists on the roadway, however this is unlikely to provide for less confident cyclists.  Where roundabouts are signalised to assist cyclists, advanced stop boxes and head-start cycle phases should be considered. 

If a roundabout is signalised, designers may also be able to include provision for cyclists (and pedestrians) to travel directly through the central island, ie a short section of off-road provision, with signalised crossings. This provides a more direct alternative to peripheral paths for cyclists travelling straight through the roundabout. Design advice for signalised roundabouts is available in the UK Department for Transport Local Transport Note 1/09.(external link)