This paper deals with a number of techniques for using signals in conjunction with roundabouts ranging from a total replacement of the roundabout to the signaling of only one or two points on it. Moreover the signals may be provided at all times or only at peak traffic periods. Attention is paid to the particular problems of signaling at roundabouts. There is a conflict between providing long cycle times required for traffic capacity and short cycle times required to accommodate queuing traffic in the limited space available. Saturation flows at signal stop lines and at give-way lines are unpredictable requiring experimentation. It is therefore valuable when commissioning signals at larger heavily-trafficked roundabouts to have them connected to a computer control system so that the settings can be varied to take account of actual traffic behaviour. For the covering abstract of the seminar see IRRD 273510.
Samenvatting