While roundabouts have been proven to reduce traffic congestion and improve safety, integrating them into a network of signalised intersections can pose challenges for maintaining efficient traffic flow. This preliminary study examines acceptable signalised intersection-roundabout distance using microsimulation analysis. The VISSIM model was designed using field data from seven roundabouts in Rijeka, Croatia, and various traffic parameters, including vehicle delay, queue lengths, fuel and CO emissions, were analysed. The findings reveal that roundabout performance improves with lower peak-hour traffic, while closer proximity to signalised intersections worsens congestion. This research underscores the importance of careful planning and consideration of traffic dynamics in optimising roundabout functionality within urban road networks.

roundabouts; microsimulations; traffic models; intersection distance; VISSIM