Shape morphing of intersections using curb side oriented driver simulation

In a traffic network, capacities of parts of the network restrict the amount of transport units which can be handled by this network. For example a two lane highway can handle a larger amount of vehicles than an access road through the forest. The capacity of a given traffic network element is not fixed but influenced by parameters such as number of lanes, maximum speed, weather, view horizon and so on. These parameters also define the maximum capacity of intersections and roundabouts. Special shapes of intersections, particularly in urban regions, may further increase or decrease their capacity. This paper investigates how the capacity of such special intersections can be estimated with only the curbsides of the intersection as an input. It is also of interest if changes to the shape decrease the amount of space “wasted” for the traffic intersection while the capacity remains unchanged. In this case study one special intersection is examined: “Central” in downtown Zurich, Switzerland. The particularity of this intersection is that it partially behaves like a roundabout but also contains two uncontrolled intersections. Due to its central position in the city, the intersection is very busy with both individual cars and public transport vehicles. In the first part of this paper, a simulation model which is able to produce realistically behaving vehicles only by using information about the curb side locations of the intersection is described The simulation shows how vehicles produce and dissolve congestion and tailbacks, demonstrating that the topology of the road configuration is a major contributor to congestion. In the second part of the paper, the simulation changes the topology of the scenario based on the observed behavior of the vehicles. Using a feedback loop allows one to optimize the capacity of the intersection while its spatial extents are minimized