Australian engineers have been using gap acceptance theory for some time. They understand most of the concepts associated with this theory and are often prepared to modify values in the light of local conditions. The appropriate gap acceptance theory for Australian roundabouts is discussed using the conclusions from observed driver interactions. As a result of these interactions, all circulating streams could be assumed to act as one. The consequences of this assumption are discussed in this paper. The method of estimating the capacity and delays at a roundabout is described here. From the brief discussion of the accident rates at roundabouts it can be confirmed that they are generally safer than other forms of control. A list of current research projects illustrates that unsignalized intersections are still considered to be a major research topic in Australia.
Abstract