Roundabouts are modelled using the well-established TRL/Kimber capacity relationships (the ARCADY Model), which take into account key roundabout geometries such as entry width, approach width, flare length, conflict angle, inscribed circle diameter and entry radius. This empirical framework intrinsically links roundabout geometry to driver behaviour and in turn to predicted capacities, queues and delays.
ARCADY has been successfully used to design and improve a number of roundabouts throughout the world. It has a host of satisfied customers including governments, multinational organisations and academic institutions. It’s simple and intuitive interface means that it can be used effectively by everyone, in a relatively short space of time.
An established Lane Simulation tool, first introduced in ARCADY 8, allows simple simulation of individual lanes to be performed on existing ARCADY models. The user can quickly see where unbalanced queuing may occur and if lane starvation may take place. The simulation takes into account the geometric layout of the roundabout, turning proportions and user-specified lane designations. Lane movements can then be altered easily using the roundabout diagram to explore and identify the optimum lane configuration.
When combined with OSCADY, it is possible to set up and model part signalised roundabouts, including signals on circulating lanes.
Features in the ARCADY Module